Feature: 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 SetMaterial: ABSWorking Voltage: AC100-230v Plug Type: EU plug 100-230v Power Consumption: 0.25w Wireless Frequency: 433mhz Working Temperature: -10°C~+45°C Ringtone Volume: ≥50db/1m Wireless Distance: 150 Meters (Open Space) Receiver Size: Approx. 78x54x20mm/3.07x2.13x0.79in Doorbell Button: No Battery Required . Package List: 1 x Doorbell1 x Receiver1 x Sticker1 x Manual