2PCS waterproof smart home electronic doorbell, long distance transmission, strong penetration Features: 1. With Memory function, no need to operate it frequently 2. Transmitter is Self-powered that requires no battery.Receiver plug indoor. 3. Ringtones: 38 pieces, with 5 level volume adjustment, Unique speaker with Loud volume 4. With silent mode, will not bother your sleep Features: Working voltage: AC100-240V 50-60Hz Working current: ?11mA(220V AC) Standby current: ?3mA?220V AC? Working distance: 100M(open space) Working frequency: 433MHZ Color: white Battery Free Wireless DoorBell with Silent Mode With Silent Mode & 38 songs music for options The Advantages Of Doorbell Main Feature Install Method 100M Remote Distance. No Wrong Encoding to Ring 1. Long press the mute button for more than 3 seconds, and enter the learning code state after a beep 2. Press the transmitter switch once, and the receiver will learn the code after a "DingDong" 3. The learning code status can last for 15 seconds, set once, and it will be permanently effective.