Kidde Carbon Monoxide Detector - Price: $10 in North Riverside, Illinois

The Kidde KNCOBLCBA is easy to install and plugs directly into a standard non-switch outlet. LED indicators light up green when power is on and red when the unit is in alarm mode. It features electromechanical sensing technology to monitor carbon monoxide levels, a 9V battery backup for continuous monitoring even during power outages, and an 85-decibel alarm. This alarm also features a low battery hush, silencing the low battery chirp warning for up to 12 hours to maintain monitoring. The unit also will go into a constant alarm mode if the unit has been unplugged or has come loose from the wall outlet.  Buyer must supply transportation.  A photo is provided.