wireless doorbell,easy for install and using,long distance for receving,the music of doorbell can be adjust by the remote contro wireless doorbellSpecification:Power Emission: 12V/DCReceiving: 4.5DC/DC 3X1.5VSIZE: C,UM2,R14 Distance: 100m (open position)Chime Sound: ≥70dbSound type: 12 or 32 kinds of music (as customers require)