Al's Liner ALS-F Vinyl Flattener (Hardener), Extra Strength Truck Bed Liner Additive, Truck Bed Liner Hardener, Truck Bed Liner Additive, Matte Finish, Undercoating - 1 Quart Achieves semi-gloss finish Matte or flat finish Increases the shore hardness and viscosity of the liner Used on exterior application where gloss is too reflective Great for hot rodders Great for use on undercoatings and Chassis Parts