Flexible Cylinder Hone for all engine applications utilizing a 3.180" to 3.500" or 83mm to 89mm bore. 100%Brand new Designed to work with cylinder bores from 3.180" to 3.500". Perfect for all engine types and block materials. 240 grit, EXCELLENT for reringing jobs or final bore. Tool is labeled as 3.50" diameter but is actually slightly larger to provide the required wall force for honing the 3 1/2" bore.