Gator 4" x 24" 40-Grit Bi-Directional Sanding Belt Sheet 2 Pack. Made of aluminum oxide abrasive material and has a cloth backing. It is suitable for bench top sanders and power belt. Gator sanding belts are designed to fit the most popular portable belt sanders offered today. These industrial-quality belts have long set the standard for quality and value. From the durable red resin bonding system, it resists heat build-up and humidity for longer life to the bi-directional flush joint that runs smoothly in both directions.