Dura-Gold Pro Series K-Block Sander Firm & Flex Hand Sanding Block Kit, 9", 16" and 24" with Hook & Loop Backing and PSA Sandpaper Conversion AdapterDura Gold Pro Series K Block Sander Firm & Flex Hand Sanding Block Kit with 3 Lengths of Sanding Blocks; Sizes 9", 16" and 24" long x 2 3 4" wide. Uniquely designed rectangle hook & loop hand sanding blocks with a 2 way design system that allows them to be used with both hook & loop and PSA sandpaper sheets. Each block includes an attachable PSA conversion adapter pad with a vinyl face that converts the blocks for use with PSA pressure sensitive