Wireless Doorbell Smart Home Welcome Chime Door Bell Self Powered Button No Battery Required Sound Alarm 36 Ringtone Receiver Wireless Self-powered Doorbell Press to generate electricity The button doesn't need a battery, just press it and it works, minus the hassle of replacing the battery. Simple and convenient installation Wireless control, no wiring, simple and convenient installation, worry-free and labor-saving Adjustable ringtone and volume 8 levels of volume and 36 ringtones to switch, receiver music can be selected as you like, there is always something you like. Easy to use The transmitter does not need wiring, no battery, is not afraid of complex houses, and the receiver is plug-and-play. Can be freely combined The transmitter and receiver support flexible code pairing, which can be arbitrarily paired. One transmitter+ multiple receivers. One receiver + multiple transmitters. Different doors, different ringtones The receiver has 36 pieces of music to choose from, and each piece of music can correspond to a transmitter individually Basic Parameters EU / US plug optional Products include Option A White doorbell (1 receiver+1 button) Option B White doorbell (2 receiver+2 button) Option C Black doorbell (1 receiver+1 button) Option D Black doorbell (2 receiver+2 button)