Blake NB72801 Centering Indicator - 4?1/4" Total Range

Looking for a faster and simpler way to center a workpiece, part or fixture? You just found it. This handy centering device works at any angle, horizontal or vertical, internal or external. Also works with NC, EDM and other hard-to-turn spindles. As the spindle rotates, the centering indicator face remains stationary and always faces the operator. That way, you free up both hands to accurately position the machine table. Use the Co-Ax Indicator with the machine spindle running, and centering conditions are closely simulated because the influence of power transmission, lubricant flow, bearing characteristics and torque are already integrated into the reading. Provides simplified method for centering workpiece or fixture on horizontal or vertical machines, external or internal diameters - also with NC, EDM and other hard to turn spindles. Includes (1) Indicator. (1) Internal feeler. (1) External feeler. (1) Restraining arm. (1) Fitted case. Weight: 9-1/2 oz. net Shipping weight: 1 lb. 14 oz. Internal capacity: 5/32" to 4-1/4" diameter External capacity: 0" to 4-1/4" diameter It is recommended that operating speed not exceed approximately 800 RPM.