Our Formula Premium catalyst, improves the quality of both petrol and diesel. The catalyst is an amalgum of metals, which react with fossil fuels to improve them. By improving the combustion process, it will lower emissions/smoke as well as improving fuel consumption/power. Made in England and lasts approx 10 years. It can either be fitted directly in the fuel line or simply dropped in the tank. The catalyst works with both diesel and petrol, plus bio fuels. When placed in the tank, it will stop fuel seperating/gumming and bacterial growth. No need to use additives of any sort. Easy to fit and comes with full fitting instructions. A full money back gaurantee is given, if not totally satisfied. Manufacturers since 1988. Distributors and stockists required in many areas.