1. Ranges of measurement: 0 toA?25D Minimum: 0.125D graduation up to A?5D 0.25D graduations over A?5D to A?25D
2. Cylinder Axis Range: 0 ~180A?step 5A?
3. Prismatic Power Range: Prism Diopter of Pattern A: at 1a?3interval in the range of 0~5a?3Prism Diopter of Pattern B: at 1a?3 interval in the range of 0~20a?3
4. Prism base angle :at 50 intervals in the range of 0 ~180 degree
5. Eyepiece Adjustment: A?5D
6. Measurand Lens Diameter: I|16 ~I|80mm