| GENERAL CHARACTERISTICS ITEM DESCRIPTION | KNIFE EDGE OUTER CONTACTS 14.53 MM APART; BALL CTR CONTACT 3.0 MM; MEASURES CONVEX,CONCAVE AND TOROIDAL SURFACES PORM 20 DIOPTERS IN 0.1 D DIV; 1.0MM CORRESPONDS TO 1.0 DIOPTER; 1.0 FULL REVOLUTION OF POINTER EQUALS 10.0 DIOPTERS; SCALE MARKINGS,CONVEX BLACK FIGURES,CONCAVE RED FIGURES; W/PLASTICBOX,INSTRUCTIONS AND CALIBRATION FLAT |