Solid-wound cylinders of Aluminum Oxide abrasive cloth. Ideal for shaping and getting into tight places you can't reach with any other polishing/grinding head. Mfg: Merit Abrasive Products, Inc. SPECS: 3⁄8" dia. x ¾" long. Grits 60; 120; 240; 320 (resin bond). 10 rolls of single grit per bag. Maximum speed: 20,000 rpm.