Garmin Premium heart rate chest strap HRM-Swim chest strap Heart rate monitoring Water rating: 5 ATM Battery: CR 2032 3V Length: 58 to 145 cm ANT+ heart rate Supports heart rate variability and advanced heart rate functions 2.4 GHz ANT radio transmission protocol Stores and forwards heart rate data Heart rate statistics for swim intervals Non-slip design for swimming pools Resistant to swimming pool chemicals