Fits securely against your body, with thin length-adjustment buckles for maximum comfortUser-replaceable batteryBasic Heart Rate Belt is compatible with Suunto M1 and M2 heart rate monitors as well as with Vector HR Fits securely against your body, with thin length-adjustment buckles for maximum comfortUser-replaceable batteryBasic Heart Rate Belt is compatible with Suunto M1 and M2 heart rate monitors as well as with Vector HR