OptiFlow Roll-On Urethane Primer is the easiest and most efficient way to get your car in a primer designed to fill imperfections, whether you\'re tackling the entire project or just doing one panel at a time! With excellent adhesion and corrosion resistance over bare steel as well as aluminum, fiberglass, body fillers and even existing finishes, it\'s the basis for a perfectly straight car with NO PAINT GUN NEEDED! Easily get your project perfectly straight with this urethane primer that sands and fills easily, saving you time and money. The finish will be so smooth everyone will think the great results came from an expensive HVLP spray gun. To properly apply this product and get the best results, you will need the OptiFlow Tray and Roller Kit . Product Benefits: Save THOUSANDS when you do it yourself, and that\'s money you can spend on an engine, wheels or more tools! No overspray (in your garage or on the neighbor\'s car) Minimal masking required No airline contamination Confidence to primer your project! Plus pride in knowing you did it yourself. Fast and easy cleanup Product Features: Easy 4:1 mix ratio with separate activator ( item 23133ZP ). Enough to cover most cars. Sands easily 4 hours application. DTM - Direct To Metal application for a strong bond. Even apply over existing coatings, fiberglass and fillers.