Features: 1.No Battery Required: Self generating wireless doorbell, wiring free, battery free, with stable signal transmission, low power consumption and environmental friendly. 2.Long Operating Range: Strong penetration, the transmission distance is greater than 150m without blocking, it is always easy to be notified when someone calls from the door. 3.High Performance: Doorbell transmitter is good sealed, with waterproof performance, not afraid of the sun, long service life, simple installation. 4.Practical: The volume of the ringtone is 50dB/1m, compact design, does not take up much space, has low power consumption, and is environmentally friendly. 5.Multifunctional: It can not only be used as a doorbell, but also as a pager, applicable for the elderly, pregnant women, patients use with simple operation. Specification: Item Type: Wireless Doorbell Set_x000D_ Material: ABS_x000D_ Working Voltage: AC100-230v_x000D_ Plug Type: EU plug 100-230v_x000D_ Power Consumption: 0.25w_x000D_ Wireless Frequency: 433mhz_x000D_ Working Temperature: -10C~+45C_x000D_ Ringtone Volume: 50db/1m_x000D_ Wireless Distance: 150 Meters (Open Space)_x000D_ Receiver Size: Approx. 78x54x20mm/3.07x2.13x0.79in_x000D_ Doorbell Button: No Battery Required PackageList: 1 xDoorbell 1 xReceiver 1 xSticker 1 x Manual