Our premounted abrasive rolls are used for sanding the inside of rings or tubes, each consists of aluminum oxide abrasive paper wrapped around a steel mandrel, creating many layers. Since paper is secured only at the bottom, user can easily tear off worn portion to expose fresh cutting surface. Unlike regular unmounted rolls, these long-lasting rolls require no truing. Supplied on a 3/32" mandrel. Maximum operating speed: 16,000 – 22,000rpm. Made in China.