Vertex Power Range +25 diopter to -25dioper Step 　0.12D & 0.25D Prismatic Power Range 5 prism diopter Step 1 diopter Cylindnical Axis Range 0 to 180 degrees Step 1 degrees Lenses Accommodated Diameter 20mm to 85mm Eyepiece Focusing -5D to +5D Bulb 220V/ 110V-6V Direct current 3V . AD & CD compatible LCD display