2 in 1 formula. Formulated for use in GM, Ford, Chrysler, and most foreign cars and light trucks. (See owners manual). Prestone Steering Fluid plus Stop Leak with Conditioner is designed to keep power steering systems running smoothly while helping to stop leaks. It is not ordinary power steering fluid. The Prestone proprietary 2 in 1 formula is a blend of the latest in power steering fluid technology and advanced stop leak additives. Prestone Power Steering Fluid plus Stop Leak is scientifically formulated to stop or reduce fluid loss caused by leaky seals. Contains a conditioner to revitalize dried, shrunken and hardened seals. One treatment stops most leaks (a second treatment may be needed if leak persists). If leak persists after second treatment, a mechanical problem may exist and you should see your service dealer. Prestone Power Steering Fluid plus Stop Leak mixes with all approved power steering fluids. Use as a preventative maintenance product.