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 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: 433 MHZ Ambient temperature:-20℃-+60℃ Plug Type:US Plug, it applies to Canada, India, Mexico, Thailand, , the , the Philippines and so on.