Flexible Cylinder Hone, Compatible Bore Diameter – Maximum 3 3/4 in, Compatible Firearm Caliber Not Applicable, Stem Diameter 0.31 in, Abrasive Length 3 1/2 in, Overall Length 13 1/2 in, Abrasive Material Aluminum Oxide, Grit 320, Operating Speed – Maximum 900 RPM, Primary Material Application Stainless Steel, Compatible Bore Diameter – Minimum 3 1/2 in, End Marking Color White, Stem Marking Color Black