Som Berthiot 8-40mm Pan-Cinor C-Mount Lens Zoomlens

It is a black cylinder with silver and black knurling at the ends, suggesting adjustment rings.
A section features a mechanism with a small red lever and a protruding black knob or switch, probably for focusing, selecting a function, or coupling.
White printed inscriptions can be seen along the side of the cylinder, including: 'PAT - CYLINDER' and '1'.
2. Angled arm/Extension tube:
A black cylindrical arm extends from an angled junction attached to the main body.
The junction displays a white inscription on its grooved surface, including: 'MADE IN FRANCE ZAEHENSKY' and possibly a serial number like '258584'.
The end of the arm also features knurlings, suggesting that it attaches to another component not fully visible in the frame. Accessories on the ground:
In front of the device, there are two caps, both black in color.
Big Cap
It appears to be a cap for a lens or for the end of a tube.
It has a raised logo in the center (it looks like a stylized figure) and the inscription 'P.A.P. BEAUBLIQUE' in white or engraved characters.
Small Cap
A smaller, simple cylindrical cap.

The item is probably an angled telescopic sight or a reflex/prismatic viewfinder for a medium format camera or movie camera, typical of vintage European optical production (in this case, French, as indicated by the writing 'MADE IN FRANCE'). Not tested.