Features and Benefits: Dura-Block conforms to the curve of the panel. Does not inset into the fill material. Hook and loop allows for the use of money-saving hook and loop paper known worldwide as the standard Gold Blocks. The product is machined for a perfect, flat finish. This 7-piece Dura-Block kit contains the most popular Dura-Blocks in money-saving hook and loop. This allows the paper to be reused when changing grains. The proprietary materials used in Dura-Blocks allow them to conform to the curve of the panel but the hardness of the surface prevents digging into filler materials. Simply the best blocks available.