Sony E-Mount adapter. It is for 4.3mm.
Entaniya Mount Adapter made by SUS304 is for holding the lens. It could be compared to an engine cylinder. If you hold it, you will be surprised about how light it is for sure.
There are E-Mount 1, E-Mount 2 and E-Mount 3. The mount to be used varies depending on the focal length of the rear group lens.
|Focal length of Rear group lens||E-Mount1||E-Mount2||E-Mount3|