First Alert Onelink SCO501CN

The First Alert Onelink SCO501CN gives protection from smoky fires as well as dangerous CO. Although it costs more than the Kidde Battery Operated Combination Carbon Monoxide and Smoke Alarm KN-COSM-B (*Est. $35), it interconnects with other Onelink models to provide continuous home protection. It operates on two AA batteries, so it doesn't require professional installation like hardwired models. The voice alert, which follows the sound of its standard horn, can be programmed to announce the location of the danger based on where the detector is located. An internal timer tracks the CO sensor's lifespan and gives an alert when the six years are up.

We found ConsumerReports.org offers the most comprehensive expert review of carbon monoxide detectors. In September 2009, editors compared the First Alert Onelink with nine other models. It's also included in a lengthy comparison chart of lifesaving features at AlarmSpecs.com. Additionally, nearly 50 owners post opinions about this detector at Amazon.com.