The Kidde C3010D provides you and your family with a loud warning signal in response to elevated levels of carbon monoxide in your home. The unit contains a 10-year tamper proof battery that eliminates the need for battery replacement, and provides continuous monitoring of CO levels, even during power outages. The digital display feature allows for easy viewing of carbon monoxide levels from 30-999 PPM (parts per million). The C3010D will also detect and store concentration levels as low as 11 and up to 999 PPM with its peak level memory display. The 10 year limited warranty lasts the life of the alarm.