DoorBellWireless Waterproof Dustproof Design Button Volume Settings and LED Indicators Operating at Over 900-feet Range with 36 Chimes (Orange) IP44 Rated Push Button: waterproof,dustproof , withstand rain, wind and other elements Long-Range: Up to 280 m/900 feet range(condition without any obstacles), work virtually anywhere in your home, strictly in compliant with FCC,CE and RoHS standard Self-learning design: A specially designed coding system ensures there is no interference to or from any nearby wireless products. Easily plug into an electrical outlet (no batteries required for main receiver).With double side stickers at the back side of the remote button Energy saving,transmitter battery can be used for over 12 months, also Ideal for calling the elderly, children, nanny or patients