Leitz Colorplan 2.5/90 Projector Lens (90mm, F2.5). This is a rare (unique?) opportunity to own a
brand new vintage Leitz lens. The lens was still sealed in its plastic bag (no box) until a few minutes ago - I only opened it so I could find out its model number/manufacturer. My father purchased this for a projector project he planned decades ago and never got around to building. The barrel of the lens is threaded and when inserted in the plastic outer tube, and rotated, varies the stick-out of the lens by about 30mm, min-to-max (presumably for focusing). Note that the outer plastic tube was loose and not in the same bag as the lens, although they clearly form a pairing.
The inner barrel (aluminium) is approximately 42.5mm in diameter (outside diameter) and the outer (plastic) barrel into which is fits has an outside diameter of approximately 45mm (minimum). When fully retracted, the whole (including lens cap) is approximately 83mm in length.
I believe that this lens is suitable for for Leica-Leitz Pradovit slide projectors but also understand that people adapt these for use as macro-lenses on cameras. I'm not an expert here, so please research online, if this is your intended application.
I have many other vintage photographic items for sale - please see my other listings.