Sungold Abrasives 024172 5" By 8 Hole 400 Grit Premium Plus C Weight Paper, Pack 5-Inch x8 Hole Hook and Loop C-Weight Non-Loading Stearate Heat Treated Aluminum Oxide Sanding Discs. An excellent all-purpose disc with a fast cut on a durable yet flexible C-weight latex impregnated backing paper. Can be used for raw wood, paints, primers and finishes, composites, fiberglass and metal. Sun gold Abrasives have been manufacturing coated abrasive products for over 37 years. Can be used for sanding of wood, metal, composites, finishes, paint.. Used for wood metal plastic fiberglass paint primer solid surface materials composites Open coat grain with a non-loading stearate minimizes loading with a cool cut for longer lasting abrasives Strong C-weight paper backing with latex impregnated paper for strong and flexible backing abrasives will not come off when folded over P graded heat treated aluminum oxide grain provides fast smooth cut while fracturing to create new cutting services extending abrasive life Full resin on resin bond adheres the grain to the cutting surface making the disc waterproof