Southern Polyurethane (SPI) Urethane Reducer is a top of the line reducer that can be used in any paint system calling for polyurethane or acrylic reducers. They are blended with top-tier solvents that can compete with any other brand of reducers regardless of price. Available in very slow, slow, medium and fast.  Very slow and fast available in gallons only and slow and medium available in both quarts and gallons.