HFS (R) Coaxial Centering Indicator Co-Ax Precision Milling Machine Test Dial CNC 23 holes includes (5) 5/8-11 threaded holes for clamping and (18) untapped holes Quick, accurate, easy centering in boring and milling set-up on horizontal or vertical machines. Operate at an angle from horizontal to vertical machines and from internal to external diameter without any change by simply changing the feeler. The face of the indicator remains stationary at any desired position while the machine spindle rotates, leaving the operator with both hands free to accurately position the table. Body length: 5-1/2"; Shank: 3/8" diameter x 7/8" long