Product Description The Kidde KN-COPP-B-LPM battery operated CO alarm provides continuous monitoring of CO levels, even during power outages when many CO incidents occur. The digital display feature allows for easy viewing of carbon monoxide levels from 30-999 PPM (parts per million). The KN-COPP-B-LPM will also detect and istore concentration CO levels as low as 11 and up to 999 PPM with its peak level memory display. This alarm, includes a slide-out battery door that gives immediate access to the batteries and a safety feature that makes it difficult to close the cover without the batteries being installed. Kidde†s KN-COPP-LPM battery-operated carbon monoxide alarm with digital display helps to provide your home with extensive protection against the dangerous threat posed by the odorless and colorless gas. With an increasing number of state and local governments passing legislation requiring CO detectors in homes, it†s never been a better time to safeguard your family against carbon monoxide exposure. View larger Features The KN-COPP-LPM is an essential device to help warn you and your family of dangerous carbon monoxide levels in your home. This alarm measures the exposure to carbon monoxide over time; it is designed to sound at 85 decibels at 10 feet when it detects 70 ppm (parts per million) of CO for 60 to 240 minutes, 150 ppm for 10 to 50 minutes, or 400 ppm for 4 to 15