Silverhook Fully Concentrated Antifreeze O.A.T. - Red provides all year round protection for up to 5 years. It is suitable for all types of engines, including aluminium. Featuring Organic Acid Technology (O.A.T.), the antifreeze prevents rust and corrosion and will also cool the engine. Freeze Protection -36C at 50% dilution. Summer protection 130C at 15 PSI and 50% dilution. Passes BS 65802010. Size 1 litre.