Type "FD-40" sections are super thick, constructed of 40-ply full disc, tightly woven industrial cotton sheeting. A perfectly balanced factory-prepared nap raked face accepts buffing compound dressing immediately. Recommended for use with Satin-Glo greaseless compounds as well as regular buffing compound rouges. Notes:Designed to be mounted on a bench grinder or similar type motor.For polishing all metals, bone paint or plastics with the application of liquid or semi-solid abrasive polishing compounds.