Kidde i12040 120VAC DC Wire-in Smoke Alarm w Battery Backup
$19.99
At RadioShack on 11-9-2008.
Protect your home with this smoke alarm from Kidde featuring ionization sensing technology. This directly-wired unit wires easily into an existing AC line, plus it has battery backup in case of a power outage. A loud 85dB alarm sounds when smoke or fire are detected. UL listed.