Kidde 9000146-LP DC CO Alarm

Monitoring CO levels constantly?even during power outages?this alarm's digital display feature allows for easy viewing of carbon monoxide levels from 30-999 PPM (parts per million). It will also detect and store concentration CO levels as low as 11 PPM and up to 999 PPM with its peak level memory display. Alarm includes a slide-out door for immediate access to the batteries and a safety feature that prevents closure when batteries are missing. 5-year warranty.