This is description of this part:
Perfect exterior and optics. It's not easy to find a lens in this condition on the used market.
Manufacturer: Hertel & Reuss Kassel (West Germany)
Model: 40:1 N.A. 0.65 PO.
Magnification: 40x
Color correction: achromat
Numerical aperture: 0.65
Tube length: 170 mm
Focal length: 37 mm
Thread: RMS
Coverglass: yes, 0,17 mm
Immersion: no
Info: polarisation objective
Of course, the "PO" designation doesn't mean it's designed "solely" for polarizing. It can be used in any microscope for both polarization and brightfield transmitted light.
What is this part needed for?
- If you don't have such a lens
- If your lens is damaged or in very poor condition
- If you need a lens with such a powerful magnification (40x) to work with polarisation
