Best for repair of fiberglass and metal surfaces. Will rebuild rotted-out areas on fenders, body sections and rocker panels. Also used for forming special customized shapes. Kit #370 contains:1 quart polyester resin, 11 cc liquid hardener, 6 sq. ft. fiberglass mat, 3″ x 5′ fiberglass tape and instructions. Kit #637 contains:8 fl.oz. resin, 1/4 oz. liquid hardener, 3 sq. ft. fiberglass cloth, mixing stick, plastic spreader, mixing tray and instructions.