Lightweight strap with a comfortable fit in a small design for use during various sports activities, Accurately measures heart rate and heart rate fluctuations Very light weight, With R-R variability memory for recordings without wearing the watch, Suitable for swimming due to water resistance up to 30 m Memory function compatible with Suunto 3, 5, 9, Spartan, Ambit 3 and Traverse watches, Great companion for Sports Tracker App with Android, iOS and Watch OS devices Long battery life of up to 500 hours, Radio compatibility with Bluetooth Smart (Bluetooth Low Energy), Comfortable material with polyurethane contact surfaces, Compatible with Movesense clothing Contents: 1x Suunto Smart Heart Rate Belt (unisex), Weight (Size M): 40,6 g, Material: polyamide/elastane/polyurethane, Size S: 56-82 cm, Size M: 70-110 cm, Size L: 96-160 cm, Temperature range: -20 to +60 °C, Colour: Black, SS050579000