Longer lifespan when sanding wood and paint! Tear-resistant X-fabric backing. Do you need a durable and strong sanding belt that you can use on rough surfaces? The PRO X440 features special reinforcements so you can get the job done over and over again. The PRO X440 sanding belt has a reinforced belt joint for stable and reliable sanding. With its tear-resistant X-fabric backing, the belt is dependable and versatile. Achieve impressive results with it.