Polar Equine V800 Heart Rate Monitor, Black Heart rate and GPS enabled multisport training device for horses Combines training load with 24/7 activity data for true recovery status. Tracks route, distance, speed/pace and altitude (via barometric altimeter) 14 hour rechargeable battery life in training mode, 50h in GPS low power mode. Scratch-resistant Gorilla Glass lens, waterproof to 100 ft Syncs to Polar Flow app and web service where you can plan and analyze training Wristband Size : 9  . NOTE - Measurements taken from the LAST HOLE to the END OF RUBBER next to buckle (not from end to end). Heart rate and GPS enabled multisport training device for horses Combines training load with 24/7 activity data for true recovery status; Tracks route, distance, speed/pace and altitude (via barometric altimeter) 14 hour rechargeable battery life in training mode, 50h in GPS low power mode; Scratch-resistant Gorilla Glass lens, waterproof to 100 ft. Syncs to Polar Flow app and web service where you can plan and analyze training