Air Systems International 2 3/4" X 6.57" X 5.1" Portable Carbon Monoxide Airline Monitor is designed for ambient air pumps and operates on 9V batteries. Portable carbon monoxide airline monitor includes external alarm and light to alert workers when damage or the contamination of the internal components if occurs and easily plugs into any high or low-pressure compressed breathing air source. It monitors the air for CO content present in the air and will activate when the CO level exceeds 10 PPM. It is supplied with 1/4" hansen coupling on 5' hose. It is recommended for applications such as portable filter pots, filter systems, equipment rentals, retrofit old style filtration systems and compressors.