APS-C diagonal fisheye announced in 2021, sold with a rear mounted ND 1000 filter. On m4/3 they declare a 150 degrees fov.
The manufacturer promotes the use on full-frame sensor cameras too. Since only panoramic photographers like cropped circular fisheyes, and the small part hood would be barely visible on the image, the idea is to make use of the 2 parts lens cap.
With the ring on, you have a mechanical vignetting, stealing precious degrees from your fov but making the circular fisheye effect very round and beautiful.