Co-Axial Indicator X 0.0005" Graduation Measuring Range: 0 ~ 4-1/4" External Capacity Diameter: 0" to 4-1/4" Accuracy: 0.0002" Restraining rod. Counterpoint feeler. The CO-AX indicator provides a simplified method for centering a workpiece or fixture on horizontal or vertical machines, external or internal diameters. Indicator dial remains stationary while the machine spindle rotates. Operates at any angle from horizontal to vertical without any change, and from internal to external by simply changing the feeler. Walking around the machine is unnecessary, no mirrors required, or no contortions. Exact chucking not needed. Graduation: 0.01mm (JD21-0002), 0.0005" (JD21-0001, JD21-0003). In a fitted plastic case. Item Range of Per Rev. Length of Straight Feeler Length of Center Point Feeler Length of Curved Feeler Face Type Description JD21-0001 0-0.15" 1.77", 4", 6.06" 2.07" 1.81", 4", 6.06" White Restraining Rod Centerpoint feeler The Centering Indicator provides a simplified method for centering a workpiece or fixture on horizontal or vertical machines, external or internal diameters Indicator dial remains stationary while the machine spindle rotates Operates at any angle from horizontal to vertical without any change and from internal to external by simply changing the feeler No walking around the machine necessary, no mirrors required, no contortions. Exact chucking not needed All points and feelers included Length of straight feeler: 1.77'', 4'', 6.06'' Length of center point feeler: 2.07'' Length of curved feeler: 1.81'', 4'', 6.06'' Mounting Shank: 3/8'' JD21-0002 0-3 mm 45, 100, 154mm 52.5mm 46, 100, 154mm Yellow With Yellow Dial Convenient tool to find and set up the position of a workpiece on vertical and horizontal machines. It can also be used to determine the position of a workpiece when the spindle is rotated by hand or automatic. Easy read-out from stationary dial indicator. The instrument with compact dimensions. Scale read-out per rotation: 0-3 mm. Graduation: 0.01 mm Max range of use: 300 mm. Centering inside and outside with various probes. 3 straight and 3 banded probes included. Center feeler included. Spindle rotating speed max. 800 rpm. Compact dimensions. For horizontal and vertical use suitable. Stem: φ10 mm. Delivery in a case. JD21-0003 0-0.15" 1.77", 4", 6.06" 2.07" 1.81", 4", 6.06" Yellow Restraining Rod Centerpoint feeler The Centering Indicator provides a simplified method for centering a workpiece or fixture on horizontal or vertical machines, external or internal diameters Indicator dial remains stationary while the machine spindle rotates Operates at any angle from horizontal to vertical without any change, and from internal to external by simply changing the feeler No walking around the machine necessary, no mirrors required, no contortions. Exact chucking not needed All points and feelers included Free Length of straight feeler: 1.77'', 4'', 6.06'' Length of center point feeler: 2.07'' Length of curved feeler: 1.81'', 4'', 6.06'' Yellow Dial Face Fitted nice wooden box Diagram of JD21-0001 and JD21-0003 Diagram of JD21-0002