---
product_id: 1259687
title: "T31 Coded Chest Transmitter and Elastic Strap"
brand: "polar"
price: "€ 96.10"
currency: EUR
in_stock: true
reviews_count: 8
category: "Polar"
url: https://www.desertcart.nl/products/1259687-t31-coded-chest-transmitter-and-elastic-strap
store_origin: NL
region: Netherlands
---

# 2500 hours battery life Water-resistant & sweat-proof 5kHz coded transmission T31 Coded Chest Transmitter and Elastic Strap

**Brand:** polar
**Price:** € 96.10
**Availability:** ✅ In Stock

## Summary

> 💪 Stay ahead of the pack with precision that never quits!

## Quick Answers

- **What is this?** T31 Coded Chest Transmitter and Elastic Strap by polar
- **How much does it cost?** € 96.10 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nl](https://www.desertcart.nl/products/1259687-t31-coded-chest-transmitter-and-elastic-strap)

## Best For

- polar enthusiasts

## Why This Product

- Trusted polar brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Sweat & Splash Proof:** Water-resistant design keeps pace with your toughest workouts.
- • **Endurance-Ready Battery:** Up to 2500 hours of uninterrupted training power—train longer, stress less.
- • **Comfort Meets Durability:** Slim, lightweight elastic strap fits 25-54 inch chests with all-day comfort.
- • **Universal Gym Compatibility:** Seamlessly syncs with Polar monitors & major gym equipment for effortless tracking.
- • **Precision Heart Rate Tracking:** Coded 5kHz signal eliminates cross-talk for ultra-accurate data.

## Overview

The Polar T31 Coded Chest Transmitter and Elastic Strap delivers reliable, coded 5kHz heart rate transmission compatible with a wide range of Polar monitors and gym equipment. Designed for accuracy, it prevents signal interference from nearby devices. Its slim, lightweight, and water-resistant build ensures comfort and durability during intense workouts. With a robust 2500-hour battery life and adjustable elastic strap fitting chest sizes 25 to 54 inches, it’s engineered for serious fitness enthusiasts seeking dependable heart rate monitoring.

## Description

Product Description Slim, light and fully water resistant transmitter that prevents cross-talk from other electrical devices for accurate measurement. desertcart.com Slim, lightweight, and water-resistant, the Polar T31 coded transmitter and belt set accurately transmits your heart rate data to your Polar wrist-top computer. As a result, it's easy to monitor your heart rate during training runs. This version of the T31 coded, meaning it prevents crosstalk from other electronic devices to ensure complete accuracy (Polar also sells a non-coded T31). It's also built to last, with a design that holds up to 2,500 hours of training usage. The transmitter belt--which works with all current Polar wrist-top computers except the CS600 and RS800--includes a sealed transmitter and elastic strap. About Polar The first EKG accurate wireless heart rate monitor was invented by Polar back in 1977 as a training tool for the Finnish National Cross Country Ski Team. The concept of "intensity training" by heart rate swept the athletic world in the eighties. By the 1990s, individuals were looking to heart rate monitors not only for performance training needs, but also for achieving everyday fitness goals. Today, the same concept of heart rate training is being used by world-class athletes as well as everyday people trying to lose weight. Polar is the leading brand among consumers, coaches, and personal trainers worldwide and the company is committed to not only producing the best products, but also being the leading educator on the benefits of heart rate based exercise.Getting Started Getting started with your T31 Coded Transmitter is easy. For best results, thoroughly moisten the back electrode areas of the transmitter with water and adjust the strap length to fit snug, but comfortable. Check that the moist electrode areas are firmly against your skin and that the Polar logo is in the upright position. Tip: When you are finished with your workout, remove the transmitter, rinse with water and dry with a soft towel. Never store the transmitter wet, in a damp environment or in any kind of non-breathable material, such as a plastic bag or sports bag. Sweat and moisture may keep the electrodes wet and the heart rate sensor activated. This will shorten the battery life. Keep in a cool and dry place. Tip: When you are finished with your workout, remove the transmitter, rinse with water and dry with a soft towel. Never store the transmitter wet, in a damp environment or in any kind of non-breathable material, such as a plastic bag or sports bag. Sweat and moisture may keep the electrodes wet and the heart rate sensor activated. This will shorten the battery life. Keep in a cool and dry place.

Review: Reliable and inexpensive alternative - I have purchased the Polar T31Coded Transmitter and Belt Set from desertcart as a replacement for my old transmitter and belt. Before bying this set, I have considered replacing just the battery itself but the cost and headache for doing it were both not worth it. Also, there was nothing even close in the price range at the Dick's Sporting Goods that I could find as these parts are not being sold by the stores. I have to say that I am NOT using the original wrist watch that came with this set due to the fact that all of the Precor aerobic machines in our gym support this set by directly reading the heart rate from the belt transmitter and displaying it on the console. It is a much better and more convinient option for me not to have to check the wrist watch and play with it so the compatibility with other exercise equipment is something I care about a lot. This product is very reliable as it took over 12 years for a battery to wear-out before I had to replace it. I am strongly recommending this product based on its longevity, durability, quality, compatibility with other equipment, and price affortibility.
Review: 2 year battery life BUT read the whole review - I bought this "NEW" in June of 2016. In July 2018 it started not broadcasting my heart rate for about the first 20 minutes every workout until it gets warm and a little sweaty, then it starts working, slowly coming down from 220 indicated BPM or so to what my actual heart rate is. (my heart doesn't go 220-bpm) There are 25 spinning bikes in the room, it does the same thing ON ALL 25 BIKES, EVERY SINGLE BIKE SAME THING, so it is not the heart rate indicator on "THE BIKE"! I have used Polar HRMs since the 1990s maybe 1980s? Within the last 5 or 10 years or so the battery life has gotten shorter and shorter. Maybe mine sat on the shelf in some department store or in some bike shop for the first 5 or 10 years of its life before I bought it "NEW" from desertcart? I honestly don't know what to do. I have to buy another one because all the equipment i use at the health club (where i work) is Polar compatible. Maybe the non-coded one is cheaper and will last longer, we will see. This is a follow up, March 2019. I tried an experiment for the last month or two. I run the transmitter under water in the sink at the health club for a second or 2, just to make it wet. I put it on wet and i go into the spinning room and it works perfectly the second i turn on the heart rate indicator on the bike. All the way through the workout it works perfectly. SO if you have one that stopped working or works intermittently, run it under water and put it on to see if that makes it work. Maybe it is an indicator that the battery is getting low but this saved me from buying a new one at this time. Good luck!

## Features

- Transmits heart rate data to Polar heart rate monitors using 5kHz transmission and compatible gym equipment. Compatible heart rate monitors include, but are not limited to: FT1, FT2, FT4, FT7, FT40, FT60, FT80, RS100, RS300X, RS400, RCX5
- Compatible products:Elastic straps.Individually coded to pick up your heart rate monitor and not others nearby. This eliminates cross-talk with other electronic devices in the same area.
- Slim, lightweight, and waterproof design
- Fits 25 to 54 inch chest size
- Average battery lifetime is 2500 hours of use. Non user replaceable battery

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B000ARDPPU |
| Battery Description | Lithium-Ion |
| Battery Life | 2500 Hours |
| Best Sellers Rank | #36,329 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) #260 in Electronics & Gadgets |
| Brand | POLAR |
| Brand Name | POLAR |
| Color | Black |
| Compatible Devices | Polar FT2 |
| Country of Origin | United States |
| Customer Reviews | 4.0 4.0 out of 5 stars (2,827) |
| Date First Available | March 12, 2003 |
| EU Spare Part Availability Duration | 1 Years |
| Global Trade Identification Number | 00725882017594, 00725882201351 |
| Included Components | Heart Rate Transmitter |
| Item Dimensions LxWxH | 0.04 x 0.04 x 0.04 inches |
| Item Package Dimensions L x W x H | 12.87 x 2.91 x 0.75 inches |
| Item Weight | 0.09 Kilograms |
| Manufacturer | Polar |
| Material | Elasticized-Fabric |
| Model Name | Polar T31 |
| Model Year | 2006 |
| Package Weight | 0.15 Kilograms |
| Part Number | 92053125 |
| Product Dimensions | 0.04"L x 0.04"W x 0.04"H |
| Screen Size | 54 Inches |
| Sensor Type | ECG |
| Size | 54" |
| Sport Type | Excercise & Fitness |
| Suggested Users | All Ages, Unisex |
| UPC | 725882017594 |
| Warranty Description | 2 year manufacturer |

## Product Details

- **Battery Description:** Lithium-Ion
- **Battery Life:** 2500 Hours
- **Brand:** POLAR
- **Color:** Black
- **Compatible Devices:** Polar FT2
- **Item Weight:** 0.09 Kilograms
- **Material:** Elasticized-Fabric
- **Product Dimensions:** 0.04"L x 0.04"W x 0.04"H
- **Screen Size:** 54 Inches
- **Sensor Type:** ECG

## Images

![T31 Coded Chest Transmitter and Elastic Strap - Image 1](https://m.media-amazon.com/images/I/614acgZzr8L.jpg)

## Questions & Answers

**Q: How do you change the battery?**
A: Although the unit is designed NOT to have the battery replaced, it can be done.  It takes a CR2032 coin type battery.I followed this video and successfully replaced mine in under ten minutes.https://youtu.be/lBsv9XoV6aA

**Q: Is it compatible  with a life fitness treadmill? If so how can it be connected?**
A: Yes it is compatible, actually I purchased for same treadmill brand . It is conected automatically by gymlink so no setup is required.  Great product .

**Q: how do you pair this t31 with compatible treadmill machines with polar sign on it?**
A: Pairing is automatic.  Just start your workout and it will sync with a little sweat

**Q: Does the t31 work with the iphone 5? I've tried without success using both MapMyRide and the Polar App. Cheers M**
A: The problem is that you need the device to be capable of acquiring data from the transmiter in it's own frequency and I do not think that the iphone is able to do that without a special additional device. For example you have a app called sports tracker that has its own heart rate monitor, I do not know how it works gut there must be some way to catch the information from the heart rate monitor to the phone. For what I know is very probable that you should need some additional device to get the heart rate monitor frequency.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Reliable and inexpensive alternative
*by S***R on September 14, 2011*

I have purchased the Polar T31Coded Transmitter and Belt Set from Amazon as a replacement for my old transmitter and belt. Before bying this set, I have considered replacing just the battery itself but the cost and headache for doing it were both not worth it. Also, there was nothing even close in the price range at the Dick's Sporting Goods that I could find as these parts are not being sold by the stores. I have to say that I am NOT using the original wrist watch that came with this set due to the fact that all of the Precor aerobic machines in our gym support this set by directly reading the heart rate from the belt transmitter and displaying it on the console. It is a much better and more convinient option for me not to have to check the wrist watch and play with it so the compatibility with other exercise equipment is something I care about a lot. This product is very reliable as it took over 12 years for a battery to wear-out before I had to replace it. I am strongly recommending this product based on its longevity, durability, quality, compatibility with other equipment, and price affortibility.

### ⭐⭐⭐⭐⭐ 2 year battery life BUT read the whole review
*by A***R on December 27, 2018*

I bought this "NEW" in June of 2016. In July 2018 it started not broadcasting my heart rate for about the first 20 minutes every workout until it gets warm and a little sweaty, then it starts working, slowly coming down from 220 indicated BPM or so to what my actual heart rate is. (my heart doesn't go 220-bpm) There are 25 spinning bikes in the room, it does the same thing ON ALL 25 BIKES, EVERY SINGLE BIKE SAME THING, so it is not the heart rate indicator on "THE BIKE"! I have used Polar HRMs since the 1990s maybe 1980s? Within the last 5 or 10 years or so the battery life has gotten shorter and shorter. Maybe mine sat on the shelf in some department store or in some bike shop for the first 5 or 10 years of its life before I bought it "NEW" from Amazon? I honestly don't know what to do. I have to buy another one because all the equipment i use at the health club (where i work) is Polar compatible. Maybe the non-coded one is cheaper and will last longer, we will see. This is a follow up, March 2019. I tried an experiment for the last month or two. I run the transmitter under water in the sink at the health club for a second or 2, just to make it wet. I put it on wet and i go into the spinning room and it works perfectly the second i turn on the heart rate indicator on the bike. All the way through the workout it works perfectly. SO if you have one that stopped working or works intermittently, run it under water and put it on to see if that makes it work. Maybe it is an indicator that the battery is getting low but this saved me from buying a new one at this time. Good luck!

### ⭐⭐⭐⭐ good transmitter
*by B***Y on February 1, 2025*

In my experience these Polar T31 transmitters work great... when they have a good battery in them. The problems come up when you buy a "new" transmitter which may have been manufactured 2 years ago? 5 years ago? 10 years ago? Since there is no manufacturing date code on the product you don't know when it was manufactured. Also you don't know if it sat in a warehouse at 120 degrees or other less than ideal battery storage temperatures for all those years. The result is the "new" transmitter may work for a week, two weeks, or two years. That said, it is pretty simple to open one of these with a knife and replace the battery (CR2032), and seal it up with some plastidip or flex-seal. The signal will be good for 12-18 months and works fine with most cardio equipment I have seen in gyms over the years. In fact it's not unusual to see my heart rate show on the machines on either side of me while I'm working out at the gym. I have a Polar 610i wrist monitor I have been using for 20+ years. In that time I have had to purchase three or four replacement T31 coded transmitters and the factory battery has never lasted more than 12 months using it for cardio workouts 3-5 times per week. So I replace the factory battery and typically every 15-18 months thereafter. When the cardio machine has problems receiving the signal I know it's time to replace, even though the wrist monitor is still recieving no problems. Eventually they do stop working and I need to buy another. This purchase (2/1/25) replaces one I purchased around 2016 which has had new batteries installed 5 or 6 times. If you don't want to replace batteries consider some other heart monitor, or spend $35 every time the battery dies.

## Frequently Bought Together

- Polar T31 Coded Chest Transmitter and Elastic Strap
- Polar H9 Heart Rate Sensor
- hengkang Fit for Polar FT4/FT7 Watch Bands, Stylish Adjustable Silicone Replacement Band Straps Wristbands Accessory Band Bracelet

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.nl/products/1259687-t31-coded-chest-transmitter-and-elastic-strap](https://www.desertcart.nl/products/1259687-t31-coded-chest-transmitter-and-elastic-strap)

---

*Product available on Desertcart Netherlands*
*Store origin: NL*
*Last updated: 2026-02-21*