This is a USC24030 Duraglas Filler. Fiber glass filled body filler, gallon. The original, premium all-purpose reinforced body filler. Repairs rusted-out areas, holes, tears & cracks on metal, wood & fiberglass. Combines resin & chopped fiberglass, giving Duraglas superior strength over ordinary plastic fillers. Can also be used with fiberglass cloth to cover large holes in a fraction of the time it takes to weld in a patch. Rust-proof & water proof. With white cream hardener.