AVANTEK DT42 Wireless Doorbell Kit 1000ft / 300m Range, 1 Transmitter & 2 Receivers Wireless doorbell kit, install battery-operated transmitter outside using adhesive mounting tape or screws, receiver chime units plugs into any standard outlet; maximum effective range 1000 ft (300 m) Up to 1000ft / 300m wireless working range, great for your apartment or office, also practical to care for the elderly or immobile patients as a paging alert device Smart design and simple controls are designed for easy installation and operation; mounting the transmitter takes only a minute, this wireless door bell is ready to go out of the box Quality design and materials for sturdy, dependable performance; available in black or white color Includes transmitter, receiver, battery, adhesive mounting tape, and instruction manual; 1-year worry-free product warranty