Property me after 2 years of active life with the Garmin 210 HR, with whom I was very happy already, now the Garmin 220 HR Incl. Premium RF chest indulged, over so 3-4 times a week, different units KM u. In any weather day evening. My positive for me differences from the 210 he are 2 freely selectable displays, the adjustable continuous light, the additional visibility in the dark, and particularly the vibrating alarm, for example. the individual KM display. (The sound I have not heard in the 210cc.) All in all, the clock is very well done, comfortable to wear and Optical MM succeeded by good. What I do can not really understand that is not a power supply more here. Roadrunner