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First Alert 9120B 120 Volt Hardwire Smoke Detectors with 9V Battery Backup

9120 120 Volt Hardwire Smoke Detectors

Regular price $10.98 Sale

Shipping/Return Policy

: In stock


  • 9V Battery Backup
  • 120VAC HARD WIRE IN - Powered by a normal 120VAC line. Includes Quick-Connect wiring harness.
  • PERFECT MOUNTING SYSTEM - features a gasketless base and a mounting bracket that keeps the alarm secure over a wide rotation range to allow for true alignment. This will allow fine-tuning on the positioning to compensate for out of aligned wall studs and to keep the wording level when wall mounting. Includes two locking features that deter theft and tampering.
  • INTERCONNECTABLE - Interconnect up to 12 alarms and 6 other interconnect devices.
  • LATCHING ALARM INDICATOR - When interconnected in a series, the unit that triggered the alarm rapidly flashes its red LED indicator. After the alarm condition subsides, the initiating unit will store in memory or latch the information and begin to flash the green LED indicator 2 seconds on, 2 seconds off.
  • 85 db LOUD ALARM - Piercing loud alarm when smoke is detected.
  • DUAL IONIZTION SENSOR - Insect screened to deter unwanted alarms.

BRK 4120 Series to 9120 Series Cross Reference Chart

Old Model No. New Model No. Description
4120 9120 AC BRK Smoke
4120-12ST 9120-12ST AC BRK Smoke in 12-pack Stadium Tray
4120 9120 AC BRK Smoke
4120AB 9120AB AC/DC BRK Smoke w/Alkaline Battery
4120B 9120B AC/DC BRK Smoke (includes silence)
4120B-48B 9120B-48B AC/DC BRK Smoke 48 bulk pack
4120B-48P 9120B-48P AC/DC BRK Smoke 48 pack
4120B-GFD 9120B-GFD AC/DC BRK Smoke Gravity Feed Display
4120LB 9120LB AC/DC BRK Smoke w/Lithium Battery
4120SAB Obsolete Not needed-Silence is a standard feature
4120SB Obsolete Not needed-Silence is a standard feature
4120SB-12ST 9120B-12ST AC/DC BRK Smoke 12 pack Stadium Tray
4120SB2 Obsolete AC/DC BRK Smoke 2 pack-Retail
4120SB-48B Obsolete Not needed-Silence is a standard feature
41206CP 91206CP AC BRK Smoke Contractor bulk 6-pack
4120SB6CP 9120B6CP AC/DC BRK Smoke Contractor bulk 6-pack
4120SB-GFD Obsolete Not needed-Silence is a standard feature
4919A 9120A AC BRK Smoke Canada
8120BL Obsolete Not needed. Latching is a standard feature.
SA4120B-48B SA9120B-48B AC/DC First Alert Smoke 48 bulk pack
SA4120CN Obsolete AC First Alert Smoke-clamshell
SA4121B-48B Obsolete Not needed-Silence is a standard feature
SA4121CN SA9121CN AC/DC First Alert Smoke-clamshell 3-pack
SC6120B SC9120B AC/DC BRK Smoke/CO combo
None SC9120B-GFD AC/DC BRK Smoke/CO Gravity Feed Display
None SC9120BA AC/DC BRK Smoke/CO combo-Canada
SC6120B-12ST SC9120B-12ST AC/DC BRK Smoke/CO combo-12-pack stadium tray
SA4121CN3 Obsolete Replaced by SA9121CN

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