Headlight Reconditioning Kit: PRESTO! PREP 1 oz., PBR 1 oz., 4 Sponges PRESTO! PREP is the only product that we know of that removes the yellowing from headlights on contact. PRESTO! PBR is an actual scratch resistant coating that is 7 times harder to scratch than typical epoxy coatings. This 1 oz. PBR bottle is enough for up to 50 headlights, depending on how heavy you apply the coating. This kit also includes die cut applicator sponges