This Air-Line hose is made of black neoprene rubber and measures 50 feet in length. It has a Hansen coupling and an inner diameter of 1/2 inch. The hose has a maximum working pressure of 300 pounds per square inch and a temperature ranging from -25 to 205 degrees Fahrenheit. It meets the NIOSH standard and is suitable for use with Ska-Pak/Ska-Pak Plus/E-Z Air-Line respirators.