The suunto smart sensor module is for use with all suunto smart sensor belts and provides live heart rate and calories burned readings as you run swim or undertake other sports and activities the bluetooth smart device is compatible with the suunto ambit3 peak ambit3 sport ambit3 run suunto movescount app sports apps for iphone android and bluetooth smart devices and it has upgradeable software and a user replaceable battery the module weighs just 10g 035oz and is water resistant t