Most known versions are the Pz.Rbl.F.5a and 5. The only significant difference is the lenght of the tube. The “5” was ment for installation in thicker cupolas. The mirrorhead is longer than the one on a Pz.B.F, but the breaking plates are the same. Both types have a fixed headrest. We have no information on the Pz.Rbl.F.2, which was only found in documents (sofar).
This is a “5a”. Made out of copper, bronze and steel, so very heavy.
Note that the inscription says: P.Rbl. in stead of the official designation Pz. You find this on more pieces of optic. The handles provide a quick change of the mirrorhead.
This is a “5”, complete with the supporting bar which was fixed on the floor in the cupola.
Peeping through the glass.
The arrow follows the angle of the head outside. A fine piece of technology.