Suunto Smart Heart Rate Sensor Black One Size. The belt provides superior performance in sports where hand movement disturbs wrist heart rate measurements and allows measuring heartrate wearing the watch on top of the sleeve or attached to the bike handlebar or even not carrying the watch at all during the exercise.? The Suunto Smart Heart Rate Belt has an R-R memory that is used when the watch is not within reach of the Bluetooth smart radio. This is great for example in team sports where it allows recording without wearing the watch. The memory function is supported with the Suunto 3 5 9 Spartan Ambit3 and Traverse watches.? Biking team sports martial arts climbing swimming water sports triathlon ski mountaineering cross country skiing skating and gym enthusiasts will see the greatest benefits from using the Suunto Smart Heart Rate Belt.? The Suunto Smart Heart Rate Belt is also a great companion for the free Sports Tracker app with Android iOS and Watch OS devices.? ?The belt included in the package is black size M. You can purchase a spare Suunto Chest Strap separately available in sizes S M and L. ? Specifications for Suunto Smart Heart Rate Sensor: Manufacturer: Suunto Color: Black Features of Suunto Smart Heart Rate Sensor Comfortable fit low weight small size Multiple sports including winter sports biking swimming and team sports? Compatible with Bluetooth smart devices / BLE devices? Heart rate measurement: Yes Heart rate variability measurement: Yes Battery life: 500 h Easy battery change: Yes Battery: CR2025 Removable transmitter module: Yes Replaceable chest strap: Yes Weight with M size belt: 406 g Smart module size: 365 x 365 x 8 mm Chest strap sizing range: S: 56-82 cm M: 70-110 cm L: 96-160 cm Water resistance: 30 m (ok for swimming) Module material: Fiber reinforced composite material Strap material: Polyamide/elastane with polyurethane contact surfaces Radio compatibility: Bluetooth Smart (Bluetooth Low Energy) Internal memory: Stores and forwards 35 h of measurement data at 120 bpm when used with compatible Suunto watch Temperature range: -20+60C Movesense apparel compatible: Yes Package Contents: Suunto Smart Heart Rate Sensor Heart Rate Belt Sensor Suunto SS050579000: Smart Heart Rate Sensor Black One Size