The PORTER-CABLE 735501825 5-Inch Hook and Loop Ao 5 Hole 180G Disc is comprised of a durable aluminum oxide grain for longer disc life and higher removal rates. The disc is resin coated to resist heat and humidity for longer life. The pressure sensitive adhesive holds securely without slipping, and the anti-clog coating resists loading. Designed for use with random orbit sanders. Commonly used for surface finishing of wood, metal, fiberglass, plastic and painted surfaces. (25 pack).