The Watch Link is compatible with any smart workout equipment that supports ANT+ or Bluetooth.

Watch Link USB: recommended for connecting to at-home equipment such as Peloton, Woodway, Hydrow, NordicTrack, Echelon, Schwinn, Wattbike, Life Fitness, Bowflex and Concept 2

Watch Link Pod: recommended for connecting to on-the-go bike computers such as Garmin and Wahoo 

The Keiser M3i bike and Schwinn 230/270 bikes are not compatible with the Watch Link as they can only connect to a special kind of heart rate monitor (called a 5Khz).