3-3/4″ (96MM) Bore Flexible Engine Cylinder Hone Bead Ball Brush 240 Grit Silicon Carbide Flexible Cylinder Hone for all engine applications utilizing a 3.500″ to 3.800″ or 89mm to 97mm bore.. 100%Brand new Designed to work with cylinder bores from 3.50″ to 3.850″. Perfect for all engine types and block materials. 240 grit, EXCELLENT for reringing jobs or final bore. The tool is labeled as a 3.750″ diameter or 95mm but is actually slightly larger to apply the required wall force Can be used with a 3/8″ or 1/2″ chuck portable drill or drill press Tool is self centering and is easy to use (inquire if you have questions).