First Alert

First Alert CO5120BN Plug-In Carbon Monoxide Alarm with Battery Backup & Digital Display

SKU CO5120BN
First Alert CO5120BN plug-in CO alarm with battery backup and digital display. Plugs into standard AC outlet. Shows live CO levels in ppm. Peak memory, test/reset. UL 2034 listed.
Technical documents available — View documents
CO Electrochemical Plug-In + Battery Backup
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First Alert CO5120BN Plug-In Carbon Monoxide Alarm

The First Alert CO5120BN plugs directly into any standard AC outlet — no tools, no wiring. An integrated battery backup keeps the alarm active even during power outages, so your family is always protected.

Continuous CO Level Monitoring

The digital display shows real-time carbon monoxide concentrations in parts per million (ppm), allowing you to monitor air quality at a glance. The Peak Level Memory captures the highest reading recorded, helping diagnose the source of a CO problem even after the alarm has cleared.

Features

  • Plug-in installation — no electrician needed
  • Battery backup for uninterrupted protection
  • Digital display – live CO ppm readout
  • Peak CO level memory
  • Electrochemical sensor for accurate, reliable detection
  • 85 dB alarm
  • UL 2034 listed

Technical Documentation