FEATURES : Coincidence focusing system 15 x eyepieces One position instrument. Measure both meridians without changing optical system Simple vertical adjustable head to fit patient Astigmatic axis 0 to 180 Degree The achromatic optical systems to precise measurement of the corneal radius curvature and accurate measurement of radius curvature of contact lens Dual eye-level sighting system Measuring range : Radius of curvature, 9.5 - 6.5 mm (in 0.25 mm steps) Dioptre 36 - 52 (in 0.25 steps) Paint finish : Black or White