firex smoke alarm 120 538b replacement

First Alert Alarm Smoke DC10 SM210 Clam Tray: 10-Year Lithium Ion Battery, Fire Alarm, No Hardwired Installation Required

First Alert® SMI100 Battery-Operated Smoke Alarm

First Alert 2pk 10-Year Battery Photoelectric Smoke Alarm with Slim Profile

First Alert 3pk Battery CO Alarm: Carbon Monoxide Detector, CO Monitor, Lithium Battery Included, No Hardwired Installation

First Alert SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup, 6-Pack

First Alert Precision Detection Interconnect Hardwired Smoke Alarm with 10-Year Battery Backup

First Alert SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup

First Alert SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup

First Alert BRK SC-9120B Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup

First Alert SMICO100-AC Interconnect Hardwire Combination Smoke & Carbon Monoxide Alarm with Battery Backup

First Alert SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup

First Alert SM100V-AC, Interconnect Hardwire Smoke Alarm with Battery Backup & Voice Alerts, 1-Pack

First Alert Smoke Alarm, Interconnect Hardwire Detector with Battery Backup, SMI100-AC, 3-Pack

First Alert SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup

First Alert SC5 Hardwire Smart Smoke & Carbon Monoxide Alarm, SMCO600NV-AC, 1-Pack, Hardwired