Have an extra strap for when the other strap is in the wash, for another user or if your elastic strap is showing wear.

Now you can use your Forerunner? for mult-sport training. Goes from wrist to bike in seconds. Includes wrist strap with quick release bracket and bike mount.

…made from a soft, fabric material. The electrodes, which pick up the heart signals, are integrated right into the strap for added flexibility and comfort. The Coded feature eliminates interference from other heart rate monitors. The F11? is the closest thing to having your own personal trainer"

This slim, light and waterproof T31 Coded transmitter offers coding to prevent cross-talk from other electrical devices for accurate measurement of your training. ECG (electrocardiogram) accurate and built to last with up to 2500 hours of training usage.

Great to have another while washing your other elastic strap, or just to have another on hand.

…created the Polar WearLink?+ 31 coded transmitter belt. It not only measures your heart rate but also seamlessly adapts to your body shapes so you feel as if it?s not even there. The transmitter consists of an electrode strap and a connector, and with its new side-clip mechanism, it?s just as quick to put…

This strap is compatible with older Polar Heart Rate Monitors (usually 7-8 years old or older).

This heart rate monitor has a soft fabric strap and is more comfortable than ever before. Plus, it's optimized for use in congested areas like gym classes and starting lines.

Measure your heart rate with (continuous) or without (non-continuous) a chest transmitter. Many features are included like target zone, calories, recovery timer and time of day.

"Our robust ANT wireless heart rate monitor with softer, more comfortable chest strap and superior battery life eliminates cross-talk with other devices to reliably measure and send heart rate data to help you train in your zone."

…and waterproof T31 doesn?t have the benefit of coding for interference free transmission. However, its purpose remains the same: to transmit your heart rate to your wrist unit ECG (electrocardiogram) accurately.

Keep your heart rate, and other training data, iin constant view on your bike or indoor exercise equipment. Simply attach the bike mount to your handlebars, strap your wrist unit on to the mount and free up your wrist.