• Front side - M77x0.75 female thred (80mm outer diameter)
• Rear side - 54mm inner diameter

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

This adapter has two functions:

1. Allows using M77x0.75 filters on lenses with 54mm front outer diameter.
2. Allows coupling such lens with a matte box with 80mm opening.

This adapter is made for Kowa 6mm lens, but can be used with other lenses with similar front size.