Features: 1.Self Powered Doorbell: 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.Long Range: The package includes 1 transmitter and 2 receivers, can be used for different rooms, and you can set separate corresponding ringtones, easy to identify. 3.Dual Purpose: 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. 4.Sound Light Alarm: When the receiver receives a signal, alarm in sound and light, convenient for the elderly and patients with ear diseases. 58 songs and 4 level adjustable volume. 5.Reliable Material: Self powered doorbell with fire retardant shell, four leaf clover pattern is pretty and fashion. IP44 grade sunscreen and waterproof, effectively prolong the service life. Specification: Item Type: Self Powered Doorbell Material: ABS Plug Voltage: AC110-240V Type: 1 Transmitter and 2 Receivers Transmitter: Power Source: Self Generated Appearance Size: Approx. 90x22mm/3.5x0.9in Ambient Temperature: -20 to +60 Transmission Distance: Approx. >150m/164yd (open space) RF Frequency: 433MHz Receiver: Power Supply: AC110-240V 50/60Hz Power Consumption: 0.25W Ringtones: 58 Ringtone Volume: 90dB Ambient Temperature: -10 to +45 PackageList: 1 x Doorbell 2 x Internal Machine 1 x Sticker 1 x Manual