Contains conditioner to revitalize seals. Scientifically formulated to stop or reduce loss of fluid caused by leaky seals due to wear or shrinkage (not effective for use with broken or scored seals). One treatment of STP Power Steering Fluid and Stop Leak (minimum of 7 oz per 1 quart power steering system - see owner"s manual for capacity) helps stop most wear or shrinkage leaks, however, additional treatments may be needed if leak persists. Contains conditioner which revitalizes dried, hardened and shrunken seals. Helps protect against wear, and stops squeals. Can be used instead of regular power steering fluid as preventative maintenance. Compatible with all approved power steering fluids.