Flexible Cylinder Hone Compatible Bore Diameter - Maximum 20 mm Compatible Firearm Caliber Not Applicable Stem Diameter 0.2 in Abrasive Length 2 1/2 in Overall Length 7 7/8 in Abrasive Material Silicon Carbide Grit 120 Compatible Tool Type Combustion Cylinder Operating Speed - Maximum 900 RPM Primary Material Application Steel End Marking Color Green Grade Coarse Stem Length 5 3/8 in