Product Parameter: Material: PC+ABS Item Color: White/Black Doorbell Transmitter Power supply: Self-powered generation Doorbell Receiver Power supply: AC 110V~230V-50/60Hz Doorbell Receiver Consumption: 0.25W Distance of transmission: 150M (No obstacles) Working frequency: 433MHz Ringtone volume:50dB Music38 Melodies Product Features: 1, Wireless, Operating range(No obstacles)150M 2, Self power generation, no battery required. 3,Installation is simple, the transmitter uses screws or double-sided tape, and the receiver is directly plugged into the socket. 4,Learning function, can realize multiple receiver or transmitter configuration EU / US / UK plugs Various plugs, voltage support AC 110V~230V-50/60Hz Self Powered,No Battery Required Energy saving and environmental protection. Don't worry if the battery has power, so Don't miss important visitors Waterproof IP68 Waterproof Grade Don't worry about extended use in heavy rain Low power consumption&Better security Upgraded IC circuit When used, No fever Designed to last up to 26 years Easy Installation No wiring required, no tools required you don't necessarily have to make holes or damage anything. NOTE:The button cannot be placed on an iron door because it will interfere with the signal. Strong signal, long transmission distance Signal is stronger, enhanced wall penetration and propagation distance 38 ring tones, 4 Volume levels Free Matching Smart Learning Code Technology,Buttons and receivers can be paired freely