M66x0.75 male to M77x0.75 female thread adapter with 80mm outer diameter

This adapter has two functions:

1. Allows using M77x0.75 filters on lenses with M66x0.75 filter thread.
2. Allows coupling such lens with a matte box with 80mm opening.

Known compatible lenses are:

1. Helios-40.

Made of anodized aluminium. Front 80 mm snap-on plastic cap is included.