3M Trizact Glass Restoration Disc (3in Medium) 3m Trizact 10 micron 3 inch Diameter with center hole for option water feed machines. Individual. Pressure sensitive adhesive (PSA) backing. Attached to any 3 inch diameter PSA type backing pad. Great for removing medium/heavy scratches in glass surfaces and many other surfaces. 3m 5 micron and polishing disc must follow this disc in this order for final clarity on glass surfaces. 3 inch Trizact material works great for repairing smaller damage on glass surfaces.