If you’re looking for a replacement heart monitor for use with your Garmin device check out the HRM-Dual. It transmits via ANT+ connectivity and BLUETOOTH Low Energy technology.
The HRM-Dual is waterproof to 1 atmosphere. The battery lasts up to 3.5 years and the soft strap is removable and washable.
buy.garmin.com/en-US/US/p/649059