Name:VT-8View Tester distance of Optical center (also known as Pupil) Range:50~75mm Step:1mm Sight Switch Ran ge:∞~380mm(distance of Optical center is64mm) Front Chin Rest Range:0~16mm Distance (from cornea vertex to the lens surface) 16mm Standard Accessories Lens two pieces of Auxiliary Cylinder -2.00m-1 and -0.12m-1 respectively Standard Accessories one piece of M2 Hexagon wrench , one piece of a Myopia Standard Card, two piece of Myopia Standard Card , one piece of standard card holder , a dust cover size 338(L)×99(W)×292(H)mm NW about5kg