First Alert 9120BFF/ SMI100-AC Smoke Detector
First Alert

First Alert 9120BFF/ SMI100-AC Smoke Detector

4.5

Best reliable hardwired safety solution for residential homeowners.

This hardwired alarm is the standard for whole-home safety, ensuring that every room triggers simultaneously if danger strikes. While the ionization sensor is specifically tuned for fast-flaming fires rather than smoldering ones, the reliable battery backup provides essential peace of mind during power outages.

$20.36

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Amazon

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Detection Technology Ionization
Dual Sensor
Ionization
Photoelectric
Power Source Hardwired with Battery Backup
Battery Operated
Hardwired with Battery Backup
Hardwired, Battery Operated
Connectivity Type Hardwired Interconnected
Hardwired Interconnected
Standalone
Interconnectivity Type Hardwired Interconnect
Hardwired Interconnect
None

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Who it's for

  • Homeowners seeking protection against fast-moving kitchen or paper fires.
  • Residents in areas prone to frequent electrical grid interruptions.
  • Families living in multi-story homes requiring whole-house notification.

Who should skip it

  • Cooks who frequently sear food or use high-heat kitchen appliances.
  • Busy individuals who prefer low-maintenance, long-term safety solutions.
  • Safety-conscious buyers looking for comprehensive, all-in-one hazard detection.

Performance breakdown

Reliability

Dual-power redundancy ensures constant protection even during unexpected electrical outages.

Excellent

Interconnectivity

Hardwired linking triggers every alarm simultaneously for maximum home-wide safety.

Excellent

Detection Speed

Ionization technology excels at identifying fast-flaming fires before they spread.

Excellent

Maintenance Ease

The integrated silence button makes handling nuisance alarms quick and simple.

Excellent

Installation Complexity

Standard hardwired setup requires basic electrical knowledge for proper installation.

Good

Feature Set

Focused on core fire safety, lacking advanced features like carbon monoxide sensing.

Good

Key Specs

Power Source

Hardwired with 9V battery backup

Detection Technology

Ionization

Connectivity Type

Hardwired Interconnected

Interconnectivity Type

Hardwired Interconnect

Battery Type

9V

Mounting Type

Ceiling or Wall Mount

Certification

UL Listed

Carbon Monoxide Detection

No

Hush Button Feature

Yes

Alert Type

Siren / Beep

Know before you buy

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Ask Metto anything about the First Alert 9120BFF/ SMI100-AC Smoke Detector before you decide.

First Alert 9120BFF/ SMI100-AC Smoke Detector

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In stock
$20.36
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