Optical micrometer is used as an attachment to the laser instrument to enable displacement of the laser parallel to itself in 2 mutually independent orthogonal planes; direct reading to0.001 in. Over range of porm 0.100 in.To accuracy of porm 0.0002 in. Over full range; has dustproof cover glass and split clamp for mounting; 1 and 1/4 pounds; auto-collimating; has graduated red and black scale reading; tolerance 0.0002 in.; (0.005 mm)