The condenser is pressed into a shuttle system and focused via rack & pinion. The mount has two centering controls (A). The polarizer is inserted below the condenser optics. Its rotational position is controlled via a graduated ring (B).
The condenser has two top lenses, both actuated by levers. Diameter = 8 or 6mm.
The Nicol prism polarizer at the base of the condenser.
Graduations show the rotational position of the polarizer.