Reco-Cool HD Expert PREMIUM 25% Pre-Diluted Antifreeze/Coolant is a ready-to-use coolant for automotive and heavy-duty diesel engines. It features hybrid organic additive technology, with low silicate and nitrite-based formulation, and does not require supplemental coolant additives (SCA) during the initial fill. This coolant is free from phosphates and amines, making it suitable for petrol and diesel engines. Designed for applications that need nitrited, low-silicate hybrid technology, it should not be diluted further with water.