The First Alert SMI100-AC Hardwire Interconnect Smoke Alarm with Battery Backup meets new industry standards utilizing First Alert's Precision Detection advance sensing technology. This hardwire smoke alarm is easy to install and replace existing alarms with no need to rewire. Plus interconnect compatible alarms to create a whole home alarm system to help provide an early warning.
The First Alert SMI100-AC Hardwire Interconnect Smoke Alarm with Battery Backup meets new industry standards utilizing First Alert's Precision Detection advance sensing technology. This hardwire smoke alarm is easy to install and replace existing alarms with no need to rewire. Plus interconnect compatible alarms to create a whole home alarm system to help provide an early warning.
in 6 offers
The lowest price for First Alert SMI100-AC Hardwire Interconnect Smoke Alarm with Battery Backup 1 Pack right now is , compared across 4 retailers.
First Alert SMI100-AC Hardwire Interconnect Smoke Alarm with Battery Backup 1 Pack
The First Alert SMI100-AC Hardwire Interconnect Smoke Alarm with Battery Backup meets new industry standards utilizing First Alert's Precision Detection advance sensing technology. This hardwire smoke alarm is easy to install and replace existing alarms with no need to rewire. Plus interconnect compatible alarms to create a whole home alarm system to help provide an early warning.
The First Alert SMI100-AC Hardwire Interconnect Smoke Alarm with Battery Backup meets new industry standards utilizing First Alert's Precision Detection advance sensing technology. This hardwire smoke alarm is easy to install and replace existing alarms with no need to rewire. Plus interconnect compatible alarms to create a whole home alarm system to help provide an early warning.
The all-time low was $32.52 on 9 June 2026 — today's price is 11% above the lowest ever. That's a little above the best price we've seen.
Prices last updated 6 Nov 2026.
Last updated at 06/11/2026 17:01:48
Brk Smi100ac Smoke Alarm, Smoke, Hardwired, Battery Backup, Smoke Detector, Ionization, Hardwired
Delivery $83.79
Hardwire Smoke Alarm
Free delivery between 17–20 Nov
Hardwire Smoke Alarm
Delivery between 13–16 Nov $29
First Alert Hardwire Smoke Alarm
Delivery $40
| Detected Substances | Smoke |
| Sensor Type | Ionization |
| Detection Method | Ionization |
| Certifications | UL 217 10th Edition Standard, STD UL2034 |
| Standards Compliance | New industry standards |
Brk Smi100ac Smoke Alarm, Smoke, Hardwired, Battery Backup, Smoke Detector, Ionization, Hardwired
Delivery $83.79
Hardwire Smoke Alarm
Free delivery between 17–20 Nov
Hardwire Smoke Alarm
Delivery between 13–16 Nov $29
First Alert Hardwire Smoke Alarm
Delivery $40
| Detected Substances | Smoke |
| Sensor Type | Ionization |
| Detection Method | Ionization |
| Certifications | UL 217 10th Edition Standard, STD UL2034 |
| Standards Compliance | New industry standards |
