Description: 1. First choose the music you want to use. 2. Press and hold the music button on the receiver until the receiver rings. 3. Press the transmitter, the receiver will sound again, and the music will be combined correctly. If paired with multiple push units in one system, the buzzer can be individually configured for each push unit. Receiving distance of 300 meters (in the open area), the receiving distance may be affected by the environment and obstacles. Stable quality is ideal for villas, hotels, schools and other areas. Simply connect the receiver to an electrical outlet, the button transmitter can be attached to the door with provided adhesive tapes. The button cannot be placed on an iron door because it will interfere with the signal. Specifications: ColorWhite/black Operating range: 300 meters in open space Volume: 4 levels of 20-80 dB Ringtones: 58 ringtones Transmitter size: 77 * 46 * 20mm Receiver size: 95 * 65 * 33mm Receiver voltage: 110-220V Receiver Plug Type: EU / UK / US Plug AU Adapter Transmitter battery type: 23A12V alkaline battery (not included) Package Included: 1 * Doorbell 1 * transmitter