A receiver and a transmitter to be a wireless doorbell, do not need to plug. 300 meters straight distance, anti-interference, 5 gears volume and 36 chord music. It can be taken as a doorbell to let the sweet ring instead of knocking, or a pager convenient for the elderly and pregnant women to call for help. Material: Plastic Color: White, Black (optional) Receiver: 3 x AA batteries (not included) Transmitter: 1 x 12V 23A battery (included) Item Size: Receiver: 95 x 65 x 25mm / 3.74 x 2.56 x 0.98in Transmitter: 75 x 51 x 20mm / 2.95 x 2.01 x 0.79in Package Weight: 150g / 5.29ounces Package Size: 120 x 90 x 70mm / 4.72 x 3.54 x 2.76in Packing List: 1 x Receiver 1 x Transmitter 1 x Doorbell Sticker 1 x Transmitter Double-sided Sticker 2 x Screws