I acquired a Thypoch Simera Z 28mm f/1.4 a few months ago. It is cheap but relatively excellent lens, but apparently has an oversized notch for the Z mount locking pin. When moving the focusing ring, the lens slops radially in the mount, cutting down on the speed and accuracy of manual focus, which is already difficult because of the long focus travel of the focus ring. Oh well. I'm still happy to use it because it outperforms my copies of the Z 28/2.8, AiS 28/2.8, and Zeiss ZF 28/2.