General description You will never miss a visitor with the AlwaysH Wireless Self-Generating Doorbell. This innovative doorbell system features a self-generating kinetic transmitter and a bell receiver, providing a reliable and convenient way for visitors to alert you from outside your home or office. Technical specifications Frequency: 433MHz RF Controlled range: approximately 200 meters Waterproof transmitter 30 melodies available 4 volume levels Installation The plug-in doorbell receiver can be easily plugged into any socket indoors. The waterproof kinetic transmitter can be installed on the outdoor door without any wiring required. Usage Pressing the transmitter generates a current that powers it, eliminating the need for batteries. Suitable for various environments including homes, farms, factories, offices, laboratories, and supermarkets.