Battery-free wireless doorbell, which generates electricity by pressing to drive wireless signals. No batteries, no wiring, simple installation, green The appearance adopts a minimalist design, simple and elegant, round and beautiful appearance, visible everywhere. It can be used with wireless receivers/smartphones Used in conjunction with switches and other receiving equipment, it is used to remotely control electrical equipment. It can easily realize single control, dual control, multi-control and mutual control. It is not only used for doorbells, but can also be used in fields such as switching pagers and so on. Doorbell receiver: Power supply:AC100V-230V 50/60Hz Power consumption:0.25W Ringtone:38 ringtones Weight:56g Ring volume: equal 50dB/1M Ambient temperature:-10℃-+45℃ Doorbell transmitter: Transmission distance:open space 150M Radio Frequency:RF 433 MHZ Ambient temperature:-20℃-+60℃ Plug Type:EU Plug,it applies to Indonesia, Germany, France, Spain, Italy and so on. Voltage:AC220V Colour:White Material:ABS Size:Doorbell receiver:Appearance size:85mmx52mmx43-63mm; Doorbell transmitter:Appearance size:L 67mm x W 33mm x H 18mm Package Contents: 1 * Doorbell Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.