The Battery-Free Wireless Doorbell is a breakthrough product with high qulaity technology. Based on radio frequency and energy harvesting technology, battery-free wireless doorbell transmitter does not need external power supply nor embedded battery to control the reciever, easy use and installation. When the button is pressed, the mechanical energy will be converted into electrical energy. Meanwhile, the transmitter will send out a radio signal to the reciever.
- Battery-Free Wireless Door Bell
- Simple install: stick – plug – ding dong
- No Battery / No Wire / No interference
- Waterproof / Suitable for cold & hot weather / Energy Saving…
- 48 songs / Volume range: 6 grade / Lifetime of 20 years