HHIP precision centering indicator features quick, accurate, easy centering in boring and milling set-up on horizontal or vertical machines. Operates at an angle from horizontal to vertical machines, and from internal to external diameter without any change by simply changing the feeler. 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. Includes: restraining rod, center point feeler, 2 inch straight feeler, 4 inch straight feeler, 6 inch straight feeler, 2 inch curved feeler, 4 inch curved feeler, 6 inch curved feeler product specifications: body Length: 5-1/2"; shank: 3/8 inch diameter x 7/8 inch long; weight: 9-1/2 oz; feeler ball: 1/8 inch diameter; measuring range: 250 Axis offset; capacity: internal 5/32 inch to 4-1/4"; dia. External 0 to 4-1/4 inch dia. Speed: spindle rotation up to; 800Rpm (exceeding this speed is not recommended) locating accuracy: 0.0002 inch of true center.