Fit many occasions: Suitable for indoor and outdoor use, such as home, office, bedroom, bathroom, kitchen, living room, etc. Waterproof: The waterproof doorbell is made of high-quality material, which can effectively prevent water from entering and keep your home clean. No battery: No battery needed, just plug it into the doorbell and you're ready to go! Good signal, strong penetration, stabilized radio frequency technology, the measured distance in the open field reaches 150 meters, and the wall penetration distance is 15-30 meters., Manufacturer: Quystetes