Durst / Schneider Componon 50mm f4 Enlarging Lens. M25 Thread with M39 Leica thread adapter ring. Used condition with marks. It has a M25 Screw Thread Mount, typical of Schneider lenses prior to the 1980's, so if your enlarger is the more recent M39 Leica screw mount, you will need to use the M39 adapter ring included.
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