Designed for the fastest possible installation! If AC power fails, the battery back-up keeps the smoke alarm working. Can be interconnected with up to 11 additional smoke alarms and 6 compatible devices like bells, repeaters or switches. Replaces discontinued models 4120b, 4120sb and 86RAC.

Features:
- Ionization Sensor
- Quick Plug-In Power Connector
- 120 VAC; Interconnectable
- Alarm Indication
- Battery Drawer Lock
- Mounting Bracket Lock
- Swing-Open Battery Door
- Battery Activation Tab
- Battery Back-Up
- AC Power Indicator
- Low Battery Warning "Chirp"
- Missing Battery Tab
- Easy Install Mounting Bracket
- 9V Battery Included

Technical Specifications:
- 120V AC
- Alarm Dimensions: 5.6” dia x 2.0”H
- Weight: 7.8 oz (9120B)
- Operating Voltage: 120V AC 60Hz w/ 9V battery backup
- Operating Current: .04 amps (standby/alarm)
- Temperature Range: 40 Degree F (4 Degree C) to 100 Degree F (38 Degree C)
- Humidity Range: 10 percent to 90 percent relative humidity (RH)
- Audio Alarm: 85dB at 10 feet

Warranty: 10 year - manufacturer

Additional Information:
Manufacturer Specification Sheet (PDF File)
Manufacturer User Manual (PDF File)