Feature:1. Self Powered Design: The doorbell set adopts self generating wireless design, no wiring, no battery, one press to convert kinetic energy into electric energy, convenient for using.2. Paging Function: Not only a doorbell, but also a pager. When a baby and the elderly sleeping alone, and pregnant women need help, they can press it, effectively protect your family.3. IP68 Waterproof Transmitter: The doorbell transmitter is IP68 waterproof and not afraid of severe weathers such as sun and rain, which can prolong the service life.4. Strong Penetration: Long distance signal transmission, strong wireless penetration through the wall, one to one signal pairing, don't worry about stringing with the next.5. Volume Adjustment: The volume is loud to solve the problem that the elderly cannot hear. You can also set one key mute mode to avoid disturbing, adjust volume at will.Specification:Item Type: Self Powered DoorbellMaterial: ABSUses: Homes, villas, hotels, factories, the elderly, patients, pregnant women for one key callType: 1 Transmitter and 2 ReceiverTransmitter Power Supply: Self GeneratedReceiver:Power Supply: AC100V-230V Power Consumption: 0.25WRingtones: 38 ringtonesTransmission Distance: Approx. >150m/164yd, Open SpaceRF Frequency: 433MHzRingtone Volume: 50dB/1m.Package List:2 x Receiver1 x Transmitter1 x Sticker1 x ManualNote:1. Do not place the product in an environment that is too humid and high temperature!2. Please supply power according to the voltage used. Using other voltages may cause fire and product damage!