Official site for Add-It. The Add-It professional range of additives and maintenance products is targeted at the professional mechanic and car enthusiast, offering high performance formulations across the entire range which consists of Brake Cleaner, Carb Cleaner, Electrical Cleaner, Engine Degreaser, Engine Flush, Radiator Flush, Clear Grease, Copper Grease, White Grease, Diesel Fuel Treatment, Petrol Treatment, Gas Leak Detector, Radiator Stop Leak, Multi-Lube and Silicone Lubricant. Explore t