In order to apply it to the machine, an additional adapter is needed, which is not included in the package and unfortunately the information is not available. Additionally, the ring is not available in Greece. As a result, you have purchased the adapter-lens from Greece and you are forced to wait for the ring from abroad.
Update 11th 2022:
if placed outside the water on the camera's mount, it traps air bubbles. It is not waterproof, so whenever the camera comes out of the water even a little, bubbles reappear.
The bubble is captured in the photo. The conclusion for me is that the purchase is not worth it at all.
I change the rating from 3 stars to 1.