Wireless Door Bell, AVANTEK CB-21 Mini Waterproof Wireless

All of the following AVANTEK doorbells with plug-in receivers can be paired with each other: CB-11/CW-11/CB-12/CW-12/CB-21/CW-21/D-3B/D-3W/D-3G/D-3F/D-3C/DB-21 (For orders purchased before 2021, it is best to tell us to inquire whether they can be paired.) With a reliable wireless range of 1,000 feet and strong signal penetration, the doorbell will never fail to alert you when someone shows up at the door. Enjoy a reliable and hassle-free doorbell system at home, in factories, offices, classrooms, apartment blocks, villas, and other large areas. The silent volume level doesn’t disturb a sleeping baby and the maximum level of 115 dB is hearable by the hearing-impaired or even during a party. The doorbell boasts an ample selection of 52 melodies from traditional doorbell chimes to jingles, certainly offering a chime that suits your taste. Thanks to its smart memory function, it remembers your previous set melody and volume level - even after a power outage. EASY TO SET UP: 2 transmitters included, can add more AVANTEK CR-1/RB-1 plug-in receivers for increased coverage; simply fix the transmitter on the wall without any wiring, includes 4 screws, 4 anchors, 1 key and 2 double-sided adhesive pads HIGH PERFORMANCE: The transmitter has ultra-low power consumption; uses a lithium battery that boasts 3-year maximum lifespan; IP55 dustproof and waterproof rating; works between -4 °F to 140 °F; withstands various harsh weather conditions MEMORY FUNCTION: Remembers your last melody and volume level after a power outage; no need to reset to your previous settings; convenient and easy-to-use design for an enhanced user experience