Kidde PI2010 Smoke Alarm Dual Sensor $17.06 FSSS @ Amazon
The Kidde PI2010 Smoke Alarm:
Price at check out
Wire-in Smoke Alarm with Reliable 9-Volt Battery Backup, Indicator LED, and Test Feature
The PI2010 is a wire-in smoke alarm with 9V battery backup, which provides continuous protection against smoke and fire hazards even during power outages. The unit offers a low battery warning that issues a brief chirp every 30 to 40 seconds for at least seven days before losing power, letting you know it's time to change the battery.
The unit measures just 5.75 inches in diameter and 1.8 inches deep, and it features a neutral, white finish. It features tamper resist features to deter vandalism or theft.
This dual-sensor smoke alarm is UL listed, so you can be confident of its quality, and it is backed by a 10-year limited warranty.