Prime Guard DEF Diesel Exhaust Fluid is an 40 pack of 2.5 Gallon Jugs designed to enhance fuel efficiency in diesel engines with SCR systems. Meeting stringent standards including EPA, ISO 22241, and DIN 70070, it ensures optimal purity. This ultra-pure, formaldehyde-free solution effectively reduces nitrogen oxides (NOx) emissions. Each jug comes with a dispensing nozzle for easy use. This API certified product is an environmentally friendly solution contributing to a healthier planet.