Battery operated 9V battery included;Test button tests unit's electronic circuitry horn and battery function;Four inch diameter discreet design;Easy installation;Meets the UL requirements and widely-accepted safety standards

• Kidde i9040 Fire Sentry Battery-Operated Ionization Sensor Compact Smoke Alarm
• 1-pack
• white

Kidde i9040 Fire Sentry Battery-Operated Ionization Sensor Compact Smoke AlarmKidde