Garmin HRM3-SS Battery Cover by jan-di | Download free STL model | Printables.com
GARMIN ANT+ HEART RATE MONITOR SPORT TRANSMITTER HRM MODULE HRM3-SS NO STRAP
Garmin HRM 3-SS will connect/pair with forerunner 35 but will not show heart rate (see picture) - Accessories & Sensors - Running/Multisport - Garmin Forums