Inateck Wireless Doorbell, IPX-6 Water-proof Door Bell with Battery-free Button Module, 80M Signal Range, 38 Bell Tones, 2 Receiver & 1 Emitter, incl. Installation Accessories, White INNOVATIVE: Due to newest energy-harvesting technology, the button does not require any batteries. Even the lightest touch on the button produces energy WEATHERPROOF: The doorbell button features the water-resistancy level IPX-6, thus opening up the possibility to install it outside DURABLE: Due to the button being designed to endure up to 200,000 presses, it boasts a high lifespan NEAT &amp; SIMPLE: The wireless door bell can be easily installed and is suited for versatile applications at home or in the garden SIGNAL RANGE: The range of the wireless signal reches up to 80 m in the open and up to 30 m indoors