Same PEAK Manufacturer as Blue DEF PEAK Diesel Exhaust Fluid Case - 2.5gal Jug per Case - Pack of 40 and 1 Pack of DEF Hero Branded Heavy Duty Absorption Wipes. Conforms to the ISO-22241-1 specification for DEF, and is an American Petroleum Institute (API) certified diesel exhaust fluid Same PEAK Manufacturer as Blue DEF. Diesel Exhaust Fluid - PEAK Diesel Exhaust Fluid is a mixture of high purity synthetic urea and deionized water that is used in Selective Catalytic Reduction (SCR) systems in diesel vehicles. DEF is used to help convert NOx to harmless nitrogen and water. Included is 1 pack of DEF Hero Branded Heavy Duty Absorption Wipes. Features: - Compatible with all diesel SCR systems - Non-flammable formula makes handling safe and easy - Conforms to the ISO-22241-1 specification for DEF, and is an American Petroleum Institute (API) certified diesel exhaust fluid - PEAK KleenDEF Diesel Exhaust Fluid is a mixture of high purity synthetic urea and deionized water that is used in Selective Catalytic Reduction (SCR) systems in diesel vehicles. DEF is used to help convert NOx to harmless nitrogen and water.