The Kidde Sealed Smoke Alarm with Ten Year Lithium Battery could very well save your life one day. This smoke alarm is completely self contained and geared to last for ten years. When the alarm begins to chirp, you’ll know that it’s near the end of its life and time to buy another one. It’s ideal for hard to reach areas, because it lasts for 10 years – so you only have to replace it one time, as opposed to 10. The choice should be easy… the Kidde Sealed Smoke Alarm with Ten Year Lithium Battery.Features Ideal for the bedroom 10 Year long life battery Sealed alarm contains 10 year battery which never needs replacement Long life power cell ideal for hard to reach areas Smart Hush button quickly silences nuisance alarms Test button and flashing LED verifies alarm and battery operation Easy to install with no wiring necessary Warning chirp sounds at the end of smoke alarm life to indicate that the alarm needs to be replaced Loud warning alarm Mounting bracket allows for fast, easy installation Mounting screws included Built in tamper - resistant feature inhibits tampering with smoke alarm Specifications Capacity: 85dB Type: 40°F to 100°F temperature range, up to 85% relative humidity Diameter: 5.6" Height: 1.55" Weight: 1.5 lb