Self-Power Wireless Doorbell1.32 Songs Home Welcome Door Chimes2.150M Long Wireless Control Distance3.Waterproof Door Bell4.Four leverls of volume5.Self-Power,No battery requiredFeatures 1 :Strong SignalIt can penetrate 3-4 walls and wireless range up to 150 meters in open area,great for large house including willas, apartment,offices,shops,warehouses.etc.Features 2 :IP68 Waterproof levelRainy days can also be used,saed and durableFeatures 3 :38 Songs Home Welcome Door ChimesThe doorbell can be muted when sleepingFeatures 4 :Not only a doorbell but also a pagerWhen the elderly,babies,and pregnant women sleeping alone have needs,press the transmitter and the bell will ring.Features 5 :Smart learning mode User-friendly designMulti-type plug interface, EU UK US Plug ,there is always one suitable for you1.Operating voltage:AC 100-230V2.Power consumption:0.25w3.Wireless frequency:433 MHz4.Operating temperature:>-10~+45C5.Ringtone volume:>50dB/1m6.Transmitter:no need battery7.Receiver size:L95xW54xH68mm8.Transmitter size:L80xW50xH28mm9.Wireless distance:150 meter(open space)