A macro lens reversing ring for (almost) every lens filter size! Currently, 30.5mm-127mm lens filter threads are supported, although the larger rings might not fit on your specific camera due to the camera grip. E-mount cameras without a grip can fit pretty much any arbitrary size.

Print with normal snug supports with the lens filter thread facing down and the E-mount facing up.

Thanks to Elijah Trufakin for the original model. The CAD file was modified to become a reversing ring instead.