42.5mm clamp to M52x1 male thread adapter for helicoids

This adapter allows using projection lenses with 42.5mm rear diameter on focusing helicoids with M52x1 thread.

A lens is secured with 3 thumb screws. Intermediate flat sping protects a lens barrel from damage by screws.

Some compatible lenses are:

• Zeiss talon/supertalon/p-sonnar
• Leica/leitz colorplan/supercolorplan/elmaron
• Braun ultralit pl
• Isco projar/cinelux/ultra mc
• Schneider ultrastar

Adapter is made of anodized aluminium. Design may be bit different from published one.