The Kidde RF-SM-DC is an AC hardwired smoke alarm that is also wireless, which makes it easier to form an interconnected alarm system, one alarm goes off…they all go off. It also sports a battery backup.
Power Source: 120 VAC w/ (3) AAA battery backup (batteries included)
Audio Alarm: 85 dB at 10 ft
Size: 5 3/4″x 1 1/4″
Weight: 8 oz
Interconnect: Up to 24 Kidde devices (18 initiating)
Warranty: 10-year limited