For sale is a Precision Hydrolic operateeed surface grinder chuck 20" dia Overall Dimensions: 25 x 27 x 17"; There are 2 types of hanels (width x depth): 7/8 x 7/8" and 1/2 x 7/8" Cercle in the center is 4" dia. Comes from a precision machine that was obsolete that I bought for parts.