Connected Doorbell and Video Door Phone -Wireless Battery Operated Door Chime - 1 Transmitter + 1 Receiver Highlights Generic Brand Wireless Battery Operated Door Chime - 1 Transmitter + 1 Receiver Description: The wireless far distance is up to 200 meters in open space, suitable for domestic and industrial use. The receiver (indoor unit) is powered by 3 AA batteries; Transmitter (outdoor unit) is powered by 1pcs 12V battery. (Battery is not included); batteries can be used for about 1 year. 36 melodies and 4-level adjustable voice volume, reminding you of your guests' arrival with lovely songs. 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. 80x45x20mm / 3.15x1.77x0.79inch Receiver Size: Approx. 120x85x30mm / 4.72x3.35x1.18inch Outdoor unit working power: 3 AA batteries Indoor unit working power: 1x 12V 23A battery Working distance: 200 meters (open space) Package includes: 1 Receiver piece Transmitter 1 piece Adhesive tape 1 piece Screw 2 pieces