Model NO.: JS2800 Lens Diameter: Max. Approx. 120mm Cylinder: 0 to 10d (0.01d \ 0.12d \0.25d Steps ) Sphere: 0 to ± 25d (0.01d \ 0.12d \0.25d Steps Add: 0 to 10d (0.01d \ 0.12d \0.25d Steps ) Prism: 0 to 10 (0.01 \ 0.12 \ 0.25 Steps