Wireless Doorbell, Ecandy Waterproof Remote Wireless Cordless Doorbell Door Chime Operating at 1000-feet Range with 52 Chimes, No Batteries Required for the Receiver Work up to 900 feet maximum (best condition without any obstacles) 52 chimes to select and 4 volume levels to alert; plenty selections offered Battery operated transmitter / push button; Wall plugged receiver; Receiver size:3.1*1.1*3.4mm; Transmitter: 2*0.7*2.8mm Easy installation, plug and play: Wire free and environment friendly, plug in socket and function normally. Radio distance reach 300 meters: Use advanced electronic technology, the wireless distance can reach 300 meters, more free and more convenient