2-Stone Hone Fits Cylinders 11/16" to 2 1/2" (17.4 - 63.5mm). Controlled pressure makes it possible to polish or hone with just one stone grit. 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. - 2 arms- 2 stones - Replacement stones are 10550 - Stones are 1 1/8" long and 3/16" wide - 10120- O-Ring * 240 Grit * Stones are interchangeable * Larger the grit, the finer the stone TOTAL LENGTH IS 8.25 INCHES