"The components include a rotating knob, an HDU spring, an HDU clip assembly, an elbow cover, an elbow, a spring, a plate, an upper barrel, a focus ring, a locking ring, an outer sleeve, a CRT cylinder, an upper barrel cylinder, a simulated HDU dust lens, a simulated HDU spool, a simulated HDU aperture, a combiner assembly 1, a mirror, a nameplate, and a gasket seal."