There are two types of optical heads available: Tilting or Fixed.
The new Tilting/Ergo Head truly resolves the headaches associated
with using a stereo microscope continuously. The Ergo head allows
up to 45 degrees of tilt/positioning capability and 180 degrees of
rotating capability to accommodate operators of any height or bench
position of the stereo microscope. The Fixed head provides a 20
degree inclination with extended eye tubes for fatigue reduced
E-Series Parallel Zoom Binocular Microscope Systems Images