Flexible Cylinder Hone, Compatible Bore Diameter – Maximum 20 mm, Compatible Firearm Caliber Not Applicable, Stem Diameter 0.19 in, Abrasive Length 2 1/2 in, Overall Length 8 in, Abrasive Material Aluminum Oxide, Grit 400, Compatible Tool Type Brake Cylinder, Wheel Cylinder, Operating Speed – Maximum 1,000 RPM, Primary Material Application Stainless Steel, Compatible Bore Diameter – Minimum 20 mm, End Marking Color Yellow, Stem Marking Color Black