Connected doorbell and videophone -Wireless battery powered door chime wireless 1 transmitter + 1 receiver (the) Highlights brand generic Wireless battery powered door chime wireless 1 transmitter + 1 receiver (the) Description : Far wireless remote distance is up to 300 meters in the open air, suitable for home and industrial use. The receiver (indoor unit) is powered by 3 AA batteries; Transmitter (outdoor unit) is powered by 1pcs 12V 23A battery. (Battery is not included); batteries can be used for about 1 year. 48 melodies and 6-level adjustable voice volume, reminding you of your guests' coming with charming songs. Also has silent mode. All-day anti-interference system, avoid interference outside or between neighbors. Simple and easy wireless installation with adhesive tape, saving trouble and money. Specification: Transmitter Size: Approx. 79x45x22mm / 3.11x1.77x0.87inch Receiver Size: Approx. 100x57x25mm / 3.94x2.25x0.98 inch Outdoor unit working power: 3 AA batteries Indoor unit working power: 1x 12V 23A battery Wireless distance: 300 meters (outdoor) Package includes: 1 set doorbell