The bellpush transmitter is powered by a 12 volts battery type 23A The Receiver plug in the mains. (230V or 110VAC) Coded to avoid intermodulation The wireless system makes installation easy and brings no effect on your interior decoration. Frequency 433. 92MHz, 418MHz Range up to (open air), R&TTE 60 meters, FCC 30 meters. Additional bellpush transmitter or receiver is available. Sounds DingDong(Double), Soft DingDong, DingDong(Single), Melody, SALAM ALAIKUM etc. There are several remotes to choose With LED flashing signal. Germany, England, French, U. S. A. , Italy, Australia types of Plugs could be chosen. Patented FCC/CE/R&TTEHS Code: 85318090 Trademark: Kangtai Model: 6898-80S Standard: FCC,CE,R&TTE Productivity: 100,200,000 Unit Price/Payment: USD3.70