2-stone hone fits cylinders 11/16" to 2-1/2" (7.4 - 63.5mm). Square ends of stones hone to the end in step-cut and blind-end cylinders. 240 grit stones are 1-1/8" long. Flexible driver. Skin-packed Controlled pressure makes it possible to polish or hone with just one stone grit on the 2 Leg 11/16" to 2 1/2" hone.