Product Reviews

Verdict: 4.2/5. The First Alert GCO1 is a plug-in combination CO and explosive-gas (methane/propane) alarm - dual-sensor coverage for homes with gas appliances.

Verdict: 4.3/5. The First Alert CO511 is a battery CO alarm with wireless interconnect and voice-location alerts - best when you want every alarm in the house to sound together.

Verdict: 4.4/5. The Kidde COPDLG is the most capable dual CO and explosive gas alarm — adds low-level CO alerts, AA battery backup, and night chirp suppression over the predecessor KN-COEG-3.

Verdict: 4.1/5. The Kidde KN-COPP-B-LPM is the most compact plug-in battery CO alarm in the lineup — identical core technology to the COPP-B family in the smallest housing for the tightest outlet clearance situations.

Verdict: 4.2/5. The Kidde KN-COPP-B-LP is the Nighthawk-branded low-profile battery plug-in CO alarm — same electrochemical sensor and digital display as the standard KN-COPP-B in a slimmer housing for tighter outlet clearance situations.

Verdict: 4.3/5. The Kidde KN-COPP-B is the best renter-friendly battery CO alarm with a digital display — battery-primary for power-outage protection, plug-in for tool-free installation, and digital ppm readout for proactive CO monitoring.

Verdict: 4.2/5. The Kidde KN-COB-IC delivers hardwired interconnect CO protection at the lowest price in the lineup — no display, no battery backup, pure interconnect alarm capability for budget-conscious multi-unit installations.

Verdict: 4.4/5. The Kidde KN-COP-IC delivers whole-home hardwired interconnect CO protection with a live digital ppm display at a lower price than the Silhouette KN-COPF-I — the right choice for multi-story homes with existing Kidde hardwired systems or new construction projects.

Verdict: 4.5/5. The Kidde KN-COP-DP-10YH is the ideal hallway CO alarm — AC plug-in with 10-year sealed battery backup, digital display, and an integrated night light for egress assistance during nighttime alarm events.

Verdict: 4.3/5. The Kidde KN-COEG-3 delivers dual CO and explosive gas protection in one plug-in unit with a digital display — the right choice for homes with natural gas or propane appliances where both hazards need coverage.

Verdict: 4.4/5. The Kidde COPDW is the best WiFi CO alarm in Kidde’s lineup — real-time smartphone alerts, AC plug-in reliability, and a backlit digital display make it the right choice for remote monitoring of vacation homes or rental properties.