Product Reviews

Verdict: 4.1/5. The First Alert CO606 is a 120V plug-in CO alarm with 9V battery backup - a no-display, set-and-forget residential pick. Not an OSHA workplace CO monitor.

Verdict: 4.3/5. The Kidde KN-COB-DP2 is the correct residential upgrade over the AC-only KN-COB-DP-LS — 9V battery backup maintains CO detection during outages. Digital display, peak memory, UL 2034 listed.