433MHZ working frequency -- The maximum transmission distance is about 200m outdoors and 50m indoors. Can pass through 3 walls without interference problems. Note: Do not install it in the metal box, as otherwise it may not be able to receive wireless signals. Waterproof & Safe -- Wireless light switch can be installed directly in the bathroom. Even with wet hands, the switch can be safely operated. To turn lamps and heaters on or off wirelessly without the risk of electric shock and without any batteries having to be protected from moisture or rust. Multi-switches control one light -- One receiver can be paired with up to 5 wireless switches, allowing you to control one light with multiple switches, avoiding the traditional complex wiring. And one wall switch can control multiple receivers. One button can turn on all devices. No battery required - You can press the switch with the wireless kinetic energy switch to generate power and send the signal. No battery required. Energy-saving and environmentally friendly. Long service life - Service life up to 50 years and up to 200,000 button presses. Control your lights inside or outside your house wherever you want (e.g., garden shed, balcony, stairs, swimming pool).