L39 Lens to Nikon-F mount adapter

Technological innovation has advanced digitization of photography systems.
Enlarger lenses which became unnecessary by digitalization are sold at auction.
Enlarger lenses are inexpensive and often have good performance.
However, because there is no focusing mechanism, it can not be used for photographing as it is.
Therefore, a photographing system with bellows was constructed.
Since the enlarger lenses is L39 mount, I made a converter to Nikon-F mount.

Note: There is no focusing feature