General description The AlwaysH Wireless Self-Generating Doorbell features a 433Mhz RF self-generating wireless system, allowing visitors to ring your indoor doorbell from the exterior transmitter. With a controlled range of approximately 200 meters, this doorbell ensures stable and reliable performance with high reception sensitivity, capable of passing through walls, floors, and doors. Technical specifications Frequency: 433Mhz Controlled range: 200 meters Melodies: 38 different options Volume levels: 4 adjustable levels Installation Plug-in bell receiver can be easily plugged into any socket indoors. Waterproof kinetic transmitter can be installed on the exterior door. No wiring is required for installation. Usage This doorbell is suitable for a wide range of applications, including homes, farms, factories, offices, laboratories, and supermarkets, ensuring you never miss a visitor.