Beseler 39mm Lensboard with Counterbore on Face (For 50-60mm Lenses)

This 39mm Lensboard is compatible with Beseler 23C, 45, and 810-series enlargers, and has a counterbore on the face of the board, making it ideally suited for 50-60mm focal length lenses when enlarging film. It also incorporates a red light pipe for illuminating the lens' aperture scale and is drilled to accept standard 39mm/M39-mount lenses.