Rislone's Diesel DEF Treatment is designed to improve DEF fluid performance and prevent white crystallization deposits from forming in the tank, pump, heater, sender, lines, injector, and mixer. The treatment works wil all UREA DEF/ AdBLue fluids to prevent crystal deposits, and will not void manufacturers' new vehicle warranties, the company stated. To use it, technicians should measure the required dosage using the chart on the bottle and pour the DEF Treatment into the DEF tank or DEF bottle/cube while refilling the tank. Sold in 8-oz. bottles, Rislone recommends using 4 oz. for light trucks and 8 oz. for medium- and heavy-duty trucks.