3M™ Hookit™ micro finishing film disc 366L is rated best in the 3M™ micro finishing line of film backed discs. It features premium, micron graded aluminum oxide abrasive bonded to a durable polyester film backing to produce a fast cut rate and uniform finish on wood, solid surface composites, plastic, fiberglass, paint prep, coating and corrosion removal, primer, e-coat or metal. We gave these discs a load resistant coating to increase efficiency and product life by minimizing loading. The abrasive is resin bonded and supports disc flexibility without sacrificing durability and reliable performance under high heat and pressure. To complement the effective abrasive action, the polyester film backing flexes to help achieve a consistent finish over contours and offers greater tear resistance than comparable paper products, making it ideal for high production environments. And the 3M™ Hookit™ attachment and removal system holds the disc securely during use and provides easy disc change out. Designed for use with orbital and random orbital sanders, this disc comes in a range of grades for complete multi-step sanding and finishing Our 3M™ Hookit™ micro finishing film disc 366L features precision, micron graded aluminum oxide, which is a popular choice among industrial professionals because of its fast cut rate and long life. This mineral makes a tough, durable abrasive that self fractures to expose fresh cutting edges, whereas traditional natural abrasives dull more quickly. Due to its fast cut rate, hardness and strength, it is widely used in grinding applications in addition to sanding and finishing applications. Aluminum oxide is suitable for a wide variety of materials in both woodworking and metalworking, including ferrous alloys. Whether the job requires a random orbital or rotary sander, buffer, grinder, drill, finishing sander or other power tool, hook and loop products allow the operator to focus more on the task and less on tooling. Abrasive products with hook and loop backing, including 3M™ Hookit™ products, are manufactured with loop material that attaches to a backup pad, sold separately, where tiny hooks firmly engage the loops. Attachment is quick, easy and secure during use. Sanding, finishing and surface conditioning products with the hook and loop attachment and removal system provide an efficient way to work through multi-step finishing processes and can be used again and again for the life of the abrasive. Our 3M™ sanding discs come in a variety of forms to fit various power tools and disc pads. Hook and loop sanding discs are designed to be used with a random orbital sander, a handheld sanding machine that rotates the disc in a random pattern to prevent swirl marks from forming on the surface of the workpiece. The sander is fitted with a backup pad (sold separately) to which the sanding disc is attached. Hook and loop discs are quick and easy to change when switching from one grade to another and can be reused again and again until worn out; whereas adhesive backed discs are typically discarded after one use because the adhesive backing will not re-adhere a second time