This will make swapping hook and loop sandpaper discs brief and simple, to stop downtime. Please Observe, When your sander doesn't have a compatible hook & loop backing, a backing pad is needed to be used, which we sell individually. Features interior and exterior circlips with straight and 90° bent https://www.hukums.com/products/insize-digital-vernier-caliper-200mm-1103-200-absoiute-system