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Kidde KN-COPE-I AC Wire-in Combo CO/Photo Smoke Alarm (21007624)

AC-Wire with battery backup An included 9V battery protects during short-term power outages
Front-loading battery with unique battery door design
Voice Warning with Green and Red LEDs
Photoelectric smoke sensor - May detect visible fire particles associated with slow smoldering fires sooner than an ionization sensor
Tamper resistant