Sinvitron Wireless Doorbell Kit with Waterproof Intelligent Touching Switch Operating at 1000 ft Range, 52 Chimes, 4-Level Volume, No Batteries Required for Receiver (S02) (1 Transmitter + 2 Receiver) Fashion design make your door elegant, high end visual effects. ABS material attributes of high rigidity which is also anti-burn and impact resistance IP55 Waterproof / Dustproof Portable Door-Bell Kit,Wireless range up to 1000 Feet (300m) in open space. Never miss any visitors. 52 Chime Options(Including 16 chords). 4 levels of adjustable volume from 25db-110db. Customize your volume easily by volume button. Flashing Light Hint. The transmitter button will flash blue light to add additional alert. The receiver will flash white light to give them a friendly hint. Easy Installation without wiring, Just plug receiver into an electrical outlet, and mount the transmitter using the supplied double sided tape or mounting screws