The center dial test indicator is a measuring tool that uses a lever to transmit the relative position of the workpiece center to the dial indicator and converts it into pointer angular displacement. It is an accurate, convenient and visible tool to find the relative center of the machined workpiece, such as the circumference and inner hole of the machined workpiece. Supporting measurement range: 0-0.15 inch, resolution: 0.0005 inches, this CO-AX coaxial centering indicator can quickly and accurately set the center for drilling and milling on horizontal or vertical machines. As the spindle rotates, the dial faces the operator, allowing him/her to center. Operation from horizontal to vertical machines and from inside to outside diameter is possible by simply replacing the inductor, without any changes. As the machine spindle rotates, the indicator surface remains stationary in any desired position, leaving the operator with both hands free to accurately position the worktable. Mounting shank: 3/8 inch. Capacity: 5/32 inch to 4-1/4 inch inside diameter or 0 to 4-1/4 inch outside diameter. Speed: Spindle rotates to 100 RPM. Exceeding this speed is not recommended. This is a professional indicator for finding the center of the workpiece on a drill or milling machine (alignment) and the center lateral diameter. Coaxial Centering Indicator x 1, Restraining Rod x 1, Center Point Sensor x 1, 2 inch, 4 inch and 6 inch Straight Plugs x 1, 2 inch, 4 inch and 6 inch Curved Plugs x 1, Twisted Wire x 2, User Manual x 1, Storage Box x 1. An essential tool set to meet your needs! Colour: As shown Material: Metal Package Contents: 1 set x coaxial indicator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.