The P4010ACSCO-CA is an AC/DC powered smoke and carbon monoxide (CO) alarm with 10 year battery backup and interconnect capability. The voice warning feature accompanies the 85dB tone during an alarm event, and helps reduce confusion with verbal announcements such as “Replace Alarm” at end of alarm life, and “Hush mode activated” when a nuisance alarm is silenced. The threecolour LED ring helps users quickly determine standby, alarm, or error mode of the alarm. Kidde P4010 Series Alarms contain 10-year tamper proof batteries that eliminate the need for battery replacement, and ends worry over unauthorized removal. The unit's Ambient Light Sensing feature establishes a day/night cycle and prevents alarm chirping in dark conditions. Hardwire interconnect triggers each connected alarm to sound once smoke or CO is detected, which can provide more time to react to a hazard. Model P4010ACSCO-CA Power Source 120 V AC, 60Hz 53mA max per alarm with sealed 3V battery backup Smoke Sensor Photoelectric CO Sensor Electrochemical Audio Alarm 85dB at 10ft Temperature Range 4.4˚C (40˚F) to 37.8˚C (100˚F) Humidity Range 10%-95% relative humidity (RH), non-condensing Size 14.2cm in diameter x 4.9cm depth Weight 0.27 kg Interconnects Up to 24 Kidde devices(of which 18 can be initiating) Warranty 10-year limited