WELCOME TO 1PlusOne Features Modern & stylish design Easy installation Approx. 500+feet operation range (open area) 5 Levels of volume (from 0dB to 110dB) 52 Ringtunes. Low power consumption Specifications Working voltage of Receiver:110-260V Battery in Transmitter:CR2032 Battery Working distance:250ft In open area. NOTE: The transmitter requires a CR2032 battery which is already included and not rechargeable. The Receiver plugs into a wall outlet and requires no battery.