Nikon 13.5cm 4.0 LS mount Parallel Focus type
This is no ordinary Nikkon 13.5cm 4.0 MIOJ screw mount lens.
It’s the very rare “Parallel Focusing type”. In the regular 13.5cm 4.0 lens the entire barrel rotated with the focusing ring, thus the front element was rotating as well. With Parallel mount only the focusing ring rotates. While the barrel moved straight in and out without turning.
A much more expensive and complex design . Produced for a very short time in tiny numbers. However, later this became a standard design.
Please reference Bob Rotoloni’s book Lens comes with shade and Front + Rear Caps.