This handblock holds your abrasive in place allowing you to achieve a flat finish. Simply cut the 230 x 280 mm sheet into 4 pieces widthways, (70mm) and place on the base of the block, folding the excess into the two flaps to hold it in place. Rubber construction makes it particularly useful when flatting panels with wet and dry sandpapers, but it is equally good with other types of abrasive papers and sheets. This handblock is not suitable for the 70x125mm velours backed sheets.