This easy to install wire free door chime set features a battery operated door button(battery included) and a wire-free door chime that simply plugs into any 3-pin mains socket. With CE, R&TTE and RoHS approvals Transmission rang: 80meters(open air) 12 different chord melodies or 16 melodies for option. Frequency: 433MHz, 315MHz Current consumption while not working <0.40mA Battery in the remote control can work for 2 yearsTechnical spec. Power supply Receiver: 230VAC, 50Hz. Transmitter: 12V(23A type battery) Range: 80m(open air) Frequency: 433.92MHz Weight(w/o battery) Receiver: 129g Transmitter: 25g