Perforated 13 sheet orbital sanding sheets the perforated holes have two banks of three parallel dust extractions holes with one at either end of the sheet the tough and sharp high performance aluminium oxide combined with a heavy paper backing makes this product extremely durable and long lasting these tough and durable sanding sheets with heavy paper backing for longer life are ideal for general purpose sanding and stock removal suitable for use on wood paint metal size 93 mm x 230 mm 13 she