Sanding Block, w/ Contoured Grip 3 1/2" x 6 1/2" (One Third Sheet) Sanding Block, w/ Contoured Grip 3 1/2" x 6 1/2" (One Third Sheet) One third sheet sanding block is constructed of sturdy plastic Comfortable contoured grip, high density foam pad base Strong spring clamp ends of sanding block hold sandpaper firmly to prevent slipping Size is approx. 3 1/2" x 6 1/2", perfect for one third sheet sanding