ACDelco 10-4082 Diesel Exhaust Emissions Reduction (DEF) Fluid - 2.5 gal Meets GM OE specifications to be approved for use in GM vehicles as well as in non-GM diesel vehicles that have an SCR system to meet regulated NOx emissions High quality formula is made from high purity urea and deionized water. It contains no chemical additives or other components that could cause SCR (Selective Catalytic Reduction) system failure Includes a vented nozzle with 1 gallon and 2.5 gallon packages that makes pouring easy by helping to prevent glugging