This is the summary of consumer reviews for Kidde KN-COPP-3 Nighthawk Plug-In Carbon Monoxide Alarm with Battery Backup and Digital Display. The BoolPool rating for this product is Good, with 3.90 stars, and the price range is $26.49-$47.29.

The Kidde KN-COPP-3 Nighthawk Plug-In Carbon Monoxide Alarm with Battery backup and Digital display is an easy to install unit that provides reliable protection against the dangers of CO. It features a digital display that shows CO levels in parts per million allowing you to see if, how and when the levels change. The Nighthawk includes a 9 volts battery backup that provides continuous monitoring of CO levels, even during power outages. This alarm gives you 3 mounting options: direct plug to a power outlet, a 6’ power cord or use it as a table top. 

With the KN-COPP-3 Nighthawk, you never have to wonder if the sensor is functioning properly. A blinking dot in the lower right-hand corner of the display denotes normal operation, so you can trust that it's working. In addition, you can test alarm function by pressing the test/reset button at any time to verify that the horn and electric circuitry are operating properly. The unit includes a peak level memory feature that will store the peak CO level sensed since the unit was last reset. The unit also features a low battery warning system.

This unit requires a fully charged battery even when plugged in the outlet.

Overall, the Kidde KN-COPP-3 Nighthawk Plug-In CO alarm is highly recommended for its safety features and reasonable price with a shelf life of 7 years.