Auto refractometer function Enlarged measurement range:It allows you to make measurement over a broad measurement range.This means you can even measure extreme myopia eye. Display screen:The CRT Monitor make the measurement results and setting image display on an easy-to-view screen. AUTO PD measurement: The PD will be automatically calculated after measurement. Easy,one-hand control:All operations,including UP\Down,Right\Left,Forward\Backward and Start can be easily controlled with one hand through the control stick. Specifications Measuring Range Spherical -20~+20D(VD=12)0.125Dsteps Cylinder -8~+8D 0.12D/0.25D steps Axis 0~180°,1°steps Pupil Distance 45~85mm,1mm steps Vertex Distance 0mm,12mm,13.75mm Min.Pupil Size 2.2mm Chart Auto fog Display 5″CRT Monitor Print Thermal Printer Power Supply 100~240V,50/60HZ Dimensions 484(L)X282(w)X440(H)mm3 Weight ~20kg(44 lb)