Product Reviews

Verdict: 4.1/5. The First Alert CO606 is the budget plug-in CO alarm with 9V battery backup for power outage protection. No display, no interconnect. Always choose over the CO600 (no backup). UL 2034 listed, 7-year warranty.

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.