The Kidde Ionization Fire Sentry™ DC Smoke Alarm is powered by one 9-Volt battery. Since there is no wiring required, there will be no loss of protection should the power go out for any reason.
Power Source: 9V battery (included)
Audio Alarm: 85 dB at 10 ft
Size: 4″x 1 7/16″
Weight: 8 oz
Warranty: 3-year limited