No 7. (Misc Lens):
It is unlabeled.
I may not see through it but I do not think it is fogged at all.
It seems all in good shape.
The optics look fine on both ends.
This may be a microscope eyepiece ??
It also may be a spectrometer which only transmits certain frequency light.
60mm long x approx 28mm dia.
Sold As Is.
As pictured.