Magnification of Eyepiece 15X Total Magnification 18X Lllumination 2X 6V/12W halogen bulb Radius of Curvature 5.5-11mm Diopter 30-60Dpt Reading Increment(radius) 0.02mm Measuring Accuracy 0.25Dpt Refrative index n used for compensation 1.3375 Minimum Surface reuired For measurement r=5.5 φ1.65 r=7.5 φ2.30 r=11φ4.00（mm） Angle Measuring Disc 0。-180。 Input Voltage 220V