The microscope includes a focusing yoke with an excursion of 50mm via rack & pinion. The yoke is intended for attachment to a 25mm diameter column. Distance from the center of the pillar bore to the center of the microscope yoke is 100mm.
The microscopes show evidence of much use, but they have been cleaned and checked for proper operation and alignment. On some of the instruments the bottom cowling bottoms against the base of the yoke. If frequent axial turning is required the cowling would need to be backed off slightly.