20 Best Rs 300x Polar [2024]

Are you looking for the best rs 300x polar? Based on expert reviews, we ranked them. We've listed our top-ranked picks, including the top-selling rs 300x polar.

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1 Arctic Animals Action Figure 48 pc Playset - Winter Habitat Adventure Toy Figures Featuring Polar... Arctic Animals Action Figure 48 pc Playset - Winter Habitat Adventure Toy Figures Featuring Polar...
2 Padgene Bluetooth Smartwatch,Touchscreen Wrist Smart Phone Watch Sports Fitness Tracker with SIM SD... Padgene Bluetooth Smartwatch,Touchscreen Wrist Smart Phone Watch Sports Fitness Tracker with SIM...
3 Polar H10 Heart Rate Monitor Chest Strap - ANT + Bluetooth, Waterproof HR Sensor for Men and Women... Polar H10 Heart Rate Monitor Chest Strap - ANT + Bluetooth, Waterproof HR Sensor for Men and...
4 EcoNour Curved Sun Blocker for Car Windshield Visor Day & Night | 2 in 1 Polarized 360 Degree... EcoNour Curved Sun Blocker for Car Windshield Visor Day & Night | 2 in 1 Polarized 360 Degree...
5 Gskyer Telescope, 70mm Aperture 400mm AZ Mount Astronomical Refracting Telescope for Kids Beginners... Gskyer Telescope, 70mm Aperture 400mm AZ Mount Astronomical Refracting Telescope for Kids...
6 7-24 ft Long Telescopic Extension Pole // Multi-Purpose Extendable Pole with Universal Twist-on... 7-24 ft Long Telescopic Extension Pole // Multi-Purpose Extendable Pole with Universal Twist-on...
7 7Pcs Polar Animals Figurines with Igloo for Kids Realistic Arctic Animal Figures Toy Playset... 7Pcs Polar Animals Figurines with Igloo for Kids Realistic Arctic Animal Figures Toy Playset...
8 Fujifilm instax Mini 9 Instant Camera (Ice Blue) with Film Twin Pack Bundle (2 Items) Fujifilm instax Mini 9 Instant Camera (Ice Blue) with Film Twin Pack Bundle (2 Items)
9 Pankoo 40X60 Monocular Telescope with Smartphone Holder & Tripod, 2021 Power Prism Compact... Pankoo 40X60 Monocular Telescope with Smartphone Holder & Tripod, 2021 Power Prism Compact...
10 Amazon Basics 60-Inch Lightweight Tripod with Bag Amazon Basics 60-Inch Lightweight Tripod with Bag
11 Polar H10 Heart Rate Monitor Chest Strap - ANT + Bluetooth, Waterproof HR Sensor for Men and Women... Polar H10 Heart Rate Monitor Chest Strap - ANT + Bluetooth, Waterproof HR Sensor for Men and...
12 Lexar Professional 1667x 128GB SDXC UHS-II Card, Up To 250MB/s Read, for Professional Photographer,... Lexar Professional 1667x 128GB SDXC UHS-II Card, Up To 250MB/s Read, for Professional...
13 Bushnell Trophy TRS-25 Red Dot Sight Riflescope, 1x20mm, Black Bushnell Trophy TRS-25 Red Dot Sight Riflescope, 1x20mm, Black
14 Polar T31 Coded Chest Transmitter and Elastic Strap - Black Polar T31 Coded Chest Transmitter and Elastic Strap - Black
15 Wireless Digital Microscope Handheld USB HD Inspection Camera 50x-1000x Magnification with Stand... Wireless Digital Microscope Handheld USB HD Inspection Camera 50x-1000x Magnification with Stand...
16 Polar H9 Heart Rate Sensor – ANT + / Bluetooth - Waterproof HR Monitor with Soft Chest Strap for... Polar H9 Heart Rate Sensor – ANT + / Bluetooth - Waterproof HR Monitor with Soft Chest Strap...
17 10-30x50 HD Monocular Telescope with Smartphone Adapter, Upgraded Tripod - High Power Zoom Monocular... 10-30x50 HD Monocular Telescope with Smartphone Adapter, Upgraded Tripod - High Power Zoom...
18 Polar H10 Heart Rate Monitor Chest Strap - ANT + Bluetooth, Waterproof HR Sensor for Men and Women... Polar H10 Heart Rate Monitor Chest Strap - ANT + Bluetooth, Waterproof HR Sensor for Men and...
19 4K 10-300X40Mm Super Telephoto Zoom Monocular Telescope, Monocular Telescope for Mobile Phone, with... 4K 10-300X40Mm Super Telephoto Zoom Monocular Telescope, Monocular Telescope for Mobile Phone,...
20 Gosky Piper Monocular Telescope, 12x55 HD Monocular for Adult with BAK4 Prism & FMC Lens,... Gosky Piper Monocular Telescope, 12x55 HD Monocular for Adult with BAK4 Prism & FMC Lens,...
Bestseller No. 1
Arctic Animals Action Figure 48 pc Playset - Winter Habitat Adventure Toy Figures Featuring Polar...
  • Arctic Habitat Action Figure Playset - 48 Piece Set Ready for Winter Adventure Toy Figures with 15 Unique Characters. Figurines are made of hard...
  • Arctic Creatures: Toy collection features a caribou, 2 huskies, polar bear cub & adult, sea lion, seal, explorer on skis, rock climber, sled,...
  • Realistic Sculpts: Set up a winter scene & get ready for an epic arctic battle of survival!
  • Gift Set for Kids: Novelty collection functions as the perfect gift set, cake topper, party favor, or just pretend play! Great for pretend play and...
  • Imaginative Play: Set encourages imaginative game play among children! Create epic battles and arctic scenes with this fun action figure set
SaleBestseller No. 2
Padgene Bluetooth Smartwatch,Touchscreen Wrist Smart Phone Watch Sports Fitness Tracker with SIM SD...
  • 🏆【Stylish Smart Watch】- With a sleek, modern design, brilliant 1.54" OLED display. Stainless steel surface, precision laminating process. Nano...
  • ⌚【Two Working Model】- ☛Bluetooth model: Just connect the smart watch with your phone via Bluetooth, then download and install the APP...
  • ⏰【Multifunctional Smart Watch】 - Activity Tracker: Pedometer, sleep monitoring, sedentary remind. Other functions: Image viewer, Sound recorder...
  • 📸【WIDE COMPATIBILITY】 - This smart watch can support most android (Full compatible)and ios phones(Function limited). Please note functions is...
  • 🎉【High Capacity Battery】 -Super high capacity 380mAh Lithium-lon battery.Gives up to 180 hours standby time and 5 hours talking time.This new...
SaleBestseller No. 3
Polar H10 Heart Rate Monitor Chest Strap - ANT + Bluetooth, Waterproof HR Sensor for Men and Women...
  • WORKS WITH EVERYTHING: Polar HRM works with many sports and smart watches (Polar, Garmin, Apple, Suunto, etc.), Polar Beat, fitness apps such as...
  • SUPREME ACCURACY: Widely recognized for its top precision by many sources, Polar H10 is the most accurate heart rate sensor in Polar’s history....
  • CONNECTIVITY: Bluetooth, ANT+ and 5 kHz provide an excellent variety of connection options (e.g. with Peloton). You can use Bluetooth and ANT+...
  • POLAR PRO CHEST STRAP: With improved electrodes, an easy-to-use buckle and silicone dots, the strap is comfortable and interference-free, and stays...
  • VERSATILITY: Wear Polar HR monitor when rowing, cycling, running, training indoors or swimming. Polar H10 is fully waterproof and it has internal...
Bestseller No. 4
EcoNour Curved Sun Blocker for Car Windshield Visor Day & Night | 2 in 1 Polarized 360 Degree...
  • Curved Polarized Lens: EcoNour Car Polarized Visor for day and night driving can help you diverge the harmful rays in an effective manner. The curved...
  • Suitable for All Weather: EcoNour Car Sun Visor works flawlessly in both daytime driving as well as night driving. The scientifically designed car...
  • Five-layer Visor Coating: The anti-shatter, polarized, and curved five-layer lens coating offers superior automotive interior sun protection while...
  • 360 Degree Rotatable: EcoNour Car 2 in 1 visor mirror is 360 degree rotatable which offers the most flexible coverage for the user. You can rotate the...
  • Easy to install: Installing the EcoNour Car Sun Visor mirror is pretty simple and all you have to do is to adjust the clamps and mount it to your...
SaleBestseller No. 5
Gskyer Telescope, 70mm Aperture 400mm AZ Mount Astronomical Refracting Telescope for Kids Beginners...
  • Quality Optics: 400mm(f/5.7) focal length and 70mm aperture, fully coated optics glass lens with high transmission coatings creates stunning images...
  • Magnification: Come with two replaceable eyepieces and one 3x Barlow lens.3x Barlow lens trebles the magnifying power of each eyepiece. 5x24 finder...
  • Wireless Remote: Free includes one smart phone adapter and one Wireless camera remote to explore the nature of the world easily through the screen and...
  • Adjustable Tripod: This telescope allows for many different viewing positions with a adjustable aluminum alloy tripod and a carry bag, the telescope...
  • Satisfaction: TWO-YEAR warranty. Technical support from our team of experts in 24 hours.
Bestseller No. 6
7-24 ft Long Telescopic Extension Pole // Multi-Purpose Extendable Pole with Universal Twist-on...
  • TO INFINITY AND BEYOND » Extending from 7 to 24 feet, the EXTEND-A-REACH retractable telescoping pole will give you up to 30 feet reach when...
  • THE ONE POLE THAT WON’T BREAK » Made of meticulously-crafted, extra-thick aluminum, this extendable painters pole is stiffer, tougher, and...
  • STAY OFF THE LADDER. STAY SAFE. GET THE JOB DONE. » Using a shaky ladder is tiring at best and dangerous at worst. Using the EXTEND-A-REACH...
  • MULTI-FUNCTIONAL TELESCOPIC EXTENSION POLE » The EXTEND-A-REACH universal attachment point fits nearly all household accessories: paint roller,...
  • EXTENDED 3-YEAR WARRANTY. EXTEND-A-REACH, FOR GOOD » We put our heart and soul into our high-reaching cleaning tools. So much so that we offer you an...
Bestseller No. 7
7Pcs Polar Animals Figurines with Igloo for Kids Realistic Arctic Animal Figures Toy Playset...
  • This Polar animals set includes 1 polar bear, 1 polar bear baby, 1 Arctic Rabbit, 1 Arctic Fox, 1 Arctic Wolf, 1 Snowy Owl and 1 Igloo with 7 Colors...
  • Natural appearance with realistic emulational details and color-tan color with different postures make the animal playset vivid. All the polar animals...
  • Widely Application. These Arctic playset are great for cake toppers, education purpose, creative play, party favors, school projects, baby shower and...
  • Awesome Birthday Gift for Children. These polar animals figurines for kids will help to improve toddlers’ concentration and outsight; Develop and...
  • These plastic polar arctic animal figures are high quality. Each figure is finely hand painted and sculpted by experts with ensures authenticity. The...
Bestseller No. 8
Fujifilm instax Mini 9 Instant Camera (Ice Blue) with Film Twin Pack Bundle (2 Items)
  • BUNDLE INCLUDES: Fujifilm instax Mini 9 Instant Camera (Ice Blue) and one Mini Film Twin Pack (20 Sheets)
  • COMPACT AND LIGHTWEIGHT DESIGN: Snaps and prints pictures that fit in your wallet. Compact and lightweight design
  • MACRO LENS AND SELFIE MIRROR: Macro Lens for close-ups from 35-50cm away, adjustable brightness and selfie mirror
  • INSTAX FILM: 2. 13 x 3. 4-Inch image size can fit in a purse, wallet or mini photo frame
Bestseller No. 9
Pankoo 40X60 Monocular Telescope with Smartphone Holder & Tripod, 2021 Power Prism Compact...
  • 【Easy to Use】 You can see scenery Easily and Rapidly by using our monocular telescope for Single Hand-Adjust the eye cup and Focus Wheel until see...
  • 【HD Dual Focus Scope】The HD monocular Scope with 419ft/1000yds(128m/1000m).40mm large objective lens,letting you look farther and see wider....
  • 【Wide Applicability】This 40x60 monocular is suitable for adults and kids,it’s a good partner for climbing, hiking, driving, racing, traveling,...
  • 【Package Accessories Includes】1xMonocular -1xSmartphone Holder -1xThree-section Stainless Steel Tripod -1xVelvet Bag -1xDust cover -1xCleaning...
SaleBestseller No. 10
Amazon Basics 60-Inch Lightweight Tripod with Bag
  • Lightweight tripod with adjustable-height legs and rubber feet
  • Compatible with most video cameras, digital cameras, still cameras, GoPro devices, smartphone adapters (not included), and scopes.
  • Recommended max load weight is 6.6 lbs (3kg) for optimal performance
  • Weighs 3 lbs; Extends from 25 inches to 60 inches when center post is fully extended; Carrying case included
  • Two built-in bubble view levels and 3-way head to allow for tilt and swivel motion; portrait or landscape options
SaleBestseller No. 11
Polar H10 Heart Rate Monitor Chest Strap - ANT + Bluetooth, Waterproof HR Sensor for Men and Women...
  • WORKS WITH EVERYTHING: Polar HRM works with many sports and smart watches (Polar, Garmin, Apple, Suunto, etc.), Polar Beat, fitness apps such as...
  • SUPREME ACCURACY: Widely recognized for its top precision by many sources, Polar H10 is the most accurate heart rate sensor in Polar’s history....
  • CONNECTIVITY: Bluetooth, ANT+ and 5 kHz provide an excellent variety of connection options (e.g. with Peloton). You can use Bluetooth and ANT+...
  • POLAR PRO CHEST STRAP: With improved electrodes, an easy-to-use buckle and silicone dots, the strap is comfortable and interference-free, and stays...
  • VERSATILITY: Wear Polar HR monitor when rowing, cycling, running, training indoors or swimming. Polar H10 is fully waterproof and it has internal...
SaleBestseller No. 12
Lexar Professional 1667x 128GB SDXC UHS-II Card, Up To 250MB/s Read, for Professional Photographer,...
  • Get high-speed performance with UHS-II technology (U3) for a read transfer speed up to 250MB/s (1667x)
  • Captures high-quality images and extended lengths of stunning 1080P full-HD, 3D, and 4K video with a DSLR camera, HD camcorder, or 3D camera
  • Large capacity options up to 256 GB let you enjoy shooting longer without changing cards
  • High-speed file transfer from card to computer to dramatically accelerate workflow
  • Backwards compatible with UHS-I devices and backed by limited lifetime product support. Operating Temperature-0° to 70° C (32°F to 158°F)
SaleBestseller No. 13
Bushnell Trophy TRS-25 Red Dot Sight Riflescope, 1x20mm, Black
  • Matte black featuring a 3 MOA Dot reticle with 11 brightness settings; Mounts easily on most picatinny rails and is compatible with pistols, shotguns,...
  • Waterproof construction: O ring sealed optics stay dry inside, even when totally immersed in water. Parallax - 50
  • Shockproof construction: Built to withstand bumps, bangs, drops and the rough and tumble environment of the field
  • Nitrogen purged fog proofing: Nitrogen inside the scope ensures interior optical surfaces won’t fog due to humidity or rapid temperature change
SaleBestseller No. 14
Polar T31 Coded Chest Transmitter and Elastic Strap - Black
  • Transmits heart rate data to Polar heart rate monitors using 5kHz transmission and compatible gym equipment. Compatible heart rate monitors include,...
  • Compatible products:Elastic straps.Individually coded to pick up your heart rate monitor and not others nearby. This eliminates cross-talk with other...
  • Slim, lightweight, and waterproof design
  • Fits 25 to 54 inch chest size
  • Average battery lifetime is 2500 hours of use. Non user replaceable battery
Bestseller No. 15
Wireless Digital Microscope Handheld USB HD Inspection Camera 50x-1000x Magnification with Stand...
  • App Provided: Optional software for IOS, Android, Windows, MacOS X. This microscope can support Android 6.0+, iOS 9.0 or later, Windows...
  • Magnification & High Definition: 2 million pixels, 1080P HD picture quality for smartphone, 720P for computer, 50x more magnification can meet your...
  • Easy to Carry: It is very easy to charge and the charge lasts for a long time. It makes for a very useful and fun tool to always have with you in the...
  • A Funny Tool: This electronic microscope is more of a fixed focus magnifying glass, not a traditional microscope, Not suitable for professional...
  • Not only a Microscope: More than a microscope, it is a camera, It can not only zoom in but also take photos and record videos. The ability to take...
Bestseller No. 16
Polar H9 Heart Rate Sensor – ANT + / Bluetooth - Waterproof HR Monitor with Soft Chest Strap for...
  • POLAR PRESENTS A NEW AFFORDABLE HRM: When you're looking for a reliable high quality heart rate monitor for your everyday sports, Polar H9 is a...
  • GOLD STANDARD IN HEART RATE TRACKING: Built on decades of scientific research and development, recognized by both regular users and researchers around...
  • EXCELLENT CONNECTIVITY OPTIONS: Polar H9 connects to sports and smart watches (Polar, Garmin, Wahoo, Zwift, Peloton), activity trackers, gym equipment...
  • NOW YOUR CARDIO WORKOUTS ARE MORE EFFECTIVE: From gym to indoor cycling via jogging and group exercise, track your heart rate and get an accurate...
  • TURN YOUR PHONE INTO A FITNESS TRACKER: Enjoy endless connection possibilities to Polar Beat, Polar Club, Peloton, Nike+ Run Club and other popular...
Bestseller No. 17
10-30x50 HD Monocular Telescope with Smartphone Adapter, Upgraded Tripod - High Power Zoom Monocular...
  • 【High Power Monocular, High Definition and Super Bright View, Clear Low Light Vision】 Advanced Fully Multi-Coated monocular provide HD vision,...
  • 【10-30x Zoom Monocular Telescope, Clearer Details】 Equipped 50mm objective diameter wide lens, provides more comfortable and larger view. High...
  • 【Upgraded Sturdy Tripod and Phone Adapter】 More sturdy tripod than others ensure clearer, brighter and shakeless images. Easily capture beauties...
  • 【Newly Universal Smartphone Adapter, Easy to Use, Fit for All Kinds of Smartphone】 Quick alignment, compatible with phone case, portable and...
  • 【Lightweight Monocular, portable hand strap, Life Waterproof】 Lightweight monocular with portable hand strap, prevents the monocular scope from...
SaleBestseller No. 18
Polar H10 Heart Rate Monitor Chest Strap - ANT + Bluetooth, Waterproof HR Sensor for Men and Women...
  • WORKS WITH EVERYTHING: Polar HRM works with many sports and smart watches (Polar, Garmin, Apple, Suunto, etc.), Polar Beat, fitness apps such as...
  • SUPREME ACCURACY: Widely recognized for its top precision by many sources, Polar H10 is the most accurate heart rate sensor in Polar's history. Polar...
  • CONNECTIVITY: Bluetooth, ANT+ and 5 kHz provide an excellent variety of connection options (e.g. with Peloton). You can use Bluetooth and ANT+...
  • POLAR PRO CHEST STRAP: With improved electrodes, an easy-to-use buckle and silicone dots, the strap is comfortable and interference-free, and stays...
  • VERSATILITY: Wear Polar HR monitor when rowing, cycling, running, training indoors or swimming. Polar H10 is fully waterproof and it has internal...
Bestseller No. 19
4K 10-300X40Mm Super Telephoto Zoom Monocular Telescope, Monocular Telescope for Mobile Phone, with...
  • ✅ Strong and durable: high-quality materials are also suitable for harsh environments. Powerful, ultra-compact, ultra-lightweight. High-quality...
  • ✅ High definition monoculars: The zoom high-definition high-power teleMonoculars adopts BAK4 prism design, which brings you clearer and colorful...
  • ✅ Widely compatible: Distortion-free and unique fixture design compatible with most smartphones and mobile devices. Used for racing, beach, bird...
  • ✅ Design with stand: The stand can better adapt to the phone, allowing you to take beautiful photos. It can also adapt to harsh environments. Note:...
  • ✅ Ideal for outdoor sports enthusiasts and wilderness explorers: Hand-held equipment is essential equipment for bird watching, wildlife, hunting,...
SaleBestseller No. 20
Gosky Piper Monocular Telescope, 12x55 HD Monocular for Adult with BAK4 Prism & FMC Lens,...
  • 12× Magnification & 55mm Objective Lens: This Gosky monocular is equipped with 12×55 high power magnification, which is the best magnification for...
  • Premium FMC Lens & BAK-4 Prism: The HD monocular telescope uses 18mm BAK-4 optics prism and FMC (Fully Multi-Coating) lens, which could increase the...
  • Lightweight Monocular & IPX7 Waterproof: The comfortable and portable hand strap could prevent the lightweight monocular scope from slipping out your...
  • Comfortable and Intimate Visual Experience: The long eye-relief that comes from the twist-up eyecup provides you with incomparable, comfortable...
  • Smartphone Adapter: Comes with a newest-version quick alignment smartphone holder, which is suitable for almost all smartphones on the market. It...

Having trouble finding a great rs 300x polar?

This problem is well understood by us because we have gone through the entire rs 300x polar research process ourselves, which is why we have put together a comprehensive list of the best rs 300x polars available in the market today.

After hours of searching and using all the models on the market, we have found the best rs 300x polar for 2023. See our ranking below!

How Do You Buy The Best Rs 300x Polar?

Do you get stressed out thinking about shopping for a great rs 300x polar? Do doubts keep creeping into your mind?

We understand, because we’ve already gone through the whole process of researching rs 300x polar, which is why we have assembled a comprehensive list of the greatest rs 300x polar available in the current market. We’ve also come up with a list of questions that you probably have yourself.

John Harvards has done the best we can with our thoughts and recommendations, but it’s still crucial that you do thorough research on your own for rs 300x polar that you consider buying. Your questions might include the following:

  • Is it worth buying an rs 300x polar?
  • What benefits are there with buying an rs 300x polar?
  • What factors deserve consideration when shopping for an effective rs 300x polar?
  • Why is it crucial to invest in any rs 300x polar, much less the best one?
  • Which rs 300x polar are good in the current market?
  • Where can you find information like this about rs 300x polar?

We’re convinced that you likely have far more questions than just these regarding rs 300x polar, and the only real way to satisfy your need for knowledge is to get information from as many reputable online sources as you possibly can.

Potential sources can include buying guides for rs 300x polar, rating websites, word-of-mouth testimonials, online forums, and product reviews. Thorough and mindful research is crucial to making sure you get your hands on the best-possible rs 300x polar. Make sure that you are only using trustworthy and credible websites and sources.

John Harvards provides an rs 300x polar buying guide, and the information is totally objective and authentic. We employ both AI and big data in proofreading the collected information.

How did we create this buying guide? We did it using a custom-created selection of algorithms that lets us manifest a top-10 list of the best available rs 300x polar currently available on the market.

This technology we use to assemble our list depends on a variety of factors, including but not limited to the following:

  1. Brand Value: Every brand of rs 300x polar has a value all its own. Most brands offer some sort of unique selling proposition that’s supposed to bring something different to the table than their competitors.
  2. Features: What bells and whistles matter for an rs 300x polar?
  3. Specifications: How powerful they are can be measured.
  4. Product Value: This simply is how much bang for the buck you get from your rs 300x polar.
  5. Customer Ratings: Number ratings grade rs 300x polar objectively.
  6. Customer Reviews: Closely related to ratings, these paragraphs give you first-hand and detailed information from real-world users about their rs 300x polar.
  7. Product Quality: You don’t always get what you pay for with an rs 300x polar, sometimes less, and sometimes more.
  8. Product Reliability: How sturdy and durable an rs 300x polar is should be an indication of how long it will work out for you.

John Harvards always remembers that maintaining rs 300x polar information to stay current is a top priority, which is why we are constantly updating our websites. Learn more about us using online sources.

If you think that anything we present here regarding rs 300x polar is irrelevant, incorrect, misleading, or erroneous, then please let us know promptly!

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FAQ:

Q: What is the polar rs300x watch?

A: Designed to help serious fitness enthusiasts study and optimize their aerobic training, the Polar RS300X is a watch and heart rate monitor in one. Smart Coaching features help you train at the proper intensity for your desired results, with educational features such as the Polar Fitness Test designed to remove guesswork from your training.

Q: Why should I buy the rs300x?

A: Get race day ready with the RS300X. It’s packed with essential running features to help you monitor your progress and maximize your training. Get all the essential heart rate features with this good-looking and simple-to-use training computer.

Q: Is the rs300x good for heart rate tracking?

A: Get all the essential heart rate features with this good-looking and simple-to-use training computer. RS300X is compatible with S1 foot pod and G1 GPS sensor, so you can combine heart rate with speed and distance. Video Player is loading.

Q: What is the size of the rs300x chest strap?

A: Every unit comes with the standard Chest Strap Wearlink size M – XXL which fits measurements from 30 – 45 inches around chest. Designed to help serious fitness enthusiasts study and optimize their aerobic training, the Polar RS300X is a watch and heart rate monitor in one.