Fit Porter Cable 343/343k, 390/390K, 382, 343VSK Orbit SanderSanders 5-Inch 8 hole round hook and loop backing pad Foam body attached to a hard plastic backing plate Easy screw-on installation Five-inch diameter, Efficient 8-hole pad works with sanders that have dust collection system One side is HOOK face, can stick with H&L sanding discs, another side is LOOP face, can stick on H&L sanding pads. 5 inch Hook and Loop Sanding Disc with 8 holes. Standard hook and loop pad (Velcro) for use with 5 inch discs. There are 8 dust collection holes to keep your work surface free of debris