3M Wetordry discs enable you to rinse areas of the workpiece and the sheet during use to prevent dust and debris from clogging the points of the abrasive and reduce air-borne dust, while producing a faster cut at the same time. These versatile discs are ideal on surfaces that tend to generate a lot of dust, such as paint, primer and wood, and can also be used dry for finishing metal and gel coats. - 3M Wetordry paper disc 431Q features extra-fast cutting silicon carbide on a strong, waterproof paper backing that gives you superior finishing for both wet and dry applications on a variety of substrates. The adhesive backing provides easy attachment to a random orbital sander.