Feature: 1. Power consumption of the doorbell is less than 3W, and the transmitter uses 12V 23A battery(include), which does not consume power if it is not pressed button. The normal use can reach more than one year. 2. Wide range of uses, in addition to being used as an ordinary doorbell, it can also be used for special purposes such as contact, paging, patient care, emergency notification, etc. 3. Using wireless high‑frequency transmission technology, innovative same‑frequency different code and dialing functions, the bit error rate is only 1/200,000. 4. Using constant voltage circuit design, achieve high efficiency and energy saving effect, the service life effectively increased by more than 50%. Effectively avoid the troubles caused by mutual interference and false noises between neighbors. Humanized and simple design. 5. No need to seek help from professionals or installers, completely free of decoration costs, no chiseling of walls, plug in indoor regular sockets, and can be used at will, and the installation position can be moved at will. Specification: Item Type: Wireless Doorbell Marterial: ABS Application: Suitable for home, shops, office, factories Ding-Dong Doorbell Working Voltage: 1.5V 2 x AA batteries (without battery)Power: ≤ 2WWorking Frequency: 315MHz Receiving Distance: ≥ Approx. 80m/87.5yd(open area)Doorbell Button Working Voltage: 12V Doorbell Button Battery Model: 23A 12V, include battery Working Current: ≤15mA. Package List: 1 x Ding-Dong Doorbell 1 x Button Doorbell1 x Battery 2 x Screw1 x Sticker