1. Operation from horizontal to vertical machines and from inside to outer diameter is possible by simply replacing the inductor without modifications. As the machine spindle rotates, the display surface remains stationary in any desired position, leaving the operator with both hands to accurately position the work table. 2. With a measuring range of 0 to 0.15 and a resolution of 0.0005, this COAX coaxial centering indicator can quickly and accurately adjust the center for drilling and milling on horizontal or vertical machines. When the spindle rotates, the scale is facing the operator, allowing him/her to center effortlessly. 3. Shaft: 3/8'. Capacity: 5/32' to 41/4' inner diameter or 0 to 41/4' outer diameter. Speed: spindle rotates at 100 min. Exceeding this speed is not recommended. This is a professional indicator for locating the workpiece center on a drilling or milling machine (alignment) and the side center diameter. 4. The dial indicator with center indicator is a measuring tool that uses a lever to transfer the relative position of the workpiece center to the dial gauge and converts it into an angular shift of the pointer. It is an accurate, practical, and visible tool to find the relative center of the machined workpiece, such as the circumference and inner hole of the machined workpiece.