General description: The wireless doorbell is designed to offer a practical and efficient solution for your home. With a range of 400 meters, it ensures reliable signal coverage without interfering with your electronic devices. Its minimalist design and easy installation make it an ideal choice for any home. Technical specifications: Waterproof rating: IP55; Range: 400 meters; Maximum volume: 110 dB; Transmitter battery life: up to 3 years; Operating temperature: -30℃ to 70℃; Transmitter power supply: 1 x 12V 23A battery; 55 different ringtones; 5 adjustable volume levels (0-110 dB). Installation: Attach the button to the wall or door frame with the included double-sided tape. Alternatively, it can be attached with the included screws, which requires a small electric drill to make holes in the wall. Do not attach the doorbell to a metal surface to avoid reducing the wireless range. Usage: The doorbell can be set to silent mode to avoid being disturbed. The blue LED light flashes when someone rings the doorbell, providing a visual signal for the hearing impaired. The memory function retains volume and ringtone settings even after the device is turned off or unplugged. Other information: 24-month warranty included. The system can be expanded by adding receivers and transmitters of the same model.