Amazon has the First Alert BRK 9120BFF Hardwired Smoke Alarm with Battery Backup, Single For $9.76 was $23.99!
Quantity 48 – 9120B hardwired smoke alarms with battery backup; bulk pack with individual packaging
Tamper resistant locking pins, single button silence/test and loud 85dB alarm
120-Volt AC power with 9-Volt battery backup (included) to keep alarm functioning during power outage
Open mounting design for easy installation with side load battery compartment for quick replacement and interconnectable up to 18 units (12 smoke, 6 CO/heat/relay)
10-Year limited warranty
