Model USI-5204 Smoke and Fire Alarm 120 Volt AC Powered. Quick Draw feature. Convenient pull-out drawer for easy battery replacement. Battery Pull-Tab - activates battery and reduces installation time. 9V battery back-up in event of AC power failure. Super Heavy Duty battery included. Full dust and contaminant cover protects the smoke alarm spray applications, thereby eliminating the need to remove the alarm during home construction. Separate Silencer Button. Convenient silencer button with automatic reset allows you to temporarily override alarm ideal for cooking smoke and fireplaces. Eliminates nuisance alarms. Interconnectable with USI AC/DC Smoke Alarms, USI Carbon Monoxide Alarms and USI Smoke and Carbon Monoxide Alarm Combination Unit. Smart interconnect up to 18 units with 12 Smoke Alarms maximum. When smoke is detected, all interconnected Smoke Alarms sound their alarm/when carbon monoxide is detected, all interconnected Carbon Monoxide Alarms sound their alarm. Originating Alarm Feature so when smoke is detected, the red LED flashes on the initiating smoke alarm. Green LED Indicator for AC power. Separate large size mounting plate attaches to any standard rectangular or octagon junction box and covers drywall cutout. Loud 85 decibel horn. Low battery audible indicator. 120 VAC 60 Hz Power. Wire harness for easy connection. Chamber and cover designs protect alarm bugs and contaminants. Five Year limited warranty. UTHA/UL Listed.