KleenDEF® KLF002 Diesel Exhaust Fuel, 2.5 GallonHighlights: Size: 2. 5 gallon Diesel exhaust fuel Stable, colorless, non flammable, non toxic A mixture of 32. 5% high purity synthetic urea & 67. 5% deionized water that is used is selective catalytic reduction systems on diesel engines Def is the primary ingredient used to help convert nox to harmless nitrogen & water classified as minimum risk for transportation Conforms to the ISO 22241 1 specification for def API registered & meets or exceeds OEM