Using the user-friendly manual, it was not a problem to activate the heart rate monitor. The transmitter in the chest strap sends after a few seconds, the heart rate of the clock. The available information are enormous for a heart rate monitor in this price range (20). Previously had a heart rate monitor with chest strap from Polar for 80, which initially worked well, but after about 2 years "gave up the ghost." Can only recommend the heart rate monitor from POWRX!