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.

…give it faster satellite reception. This model ships with a new waterproof soft-strap heart rate monitor, streamlined and more comfortable than ever, yet rugged enough to withstand swimming (note: heart rate data not available while monitor is in water).

…GPS navigator perfect for outdoor activities that require the use of both hands. Foretrex 301 combines a high-sensitivity GPS receiver, rugged, waterproof design and USB interface into a lightweight device ideal for hikers, skiers, campers and military personnel.

…a slim wrist-mounted GPS navigator perfect for outdoor activities that require the use of both hands. Foretrex 401 combines a high-sensitivity waterproof GPS receiver, electronic compass and barometric altimeter into a lightweight device ideal for hikers, skiers, campers and military personnel. To…

This slim, light 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.