Breech adapter for APS shells as the Hwasan shells are much larger.
Two required for the set.
Big thanks to James Smith on YouTube for creating this tutorial video on the installation and testing of this kit.
Steel option was put up as a request, however due to the tolerances of steel prints, please make sure you are prepared to do the sanding (both inside and outside) in order for it to run smoothly, the plastic version, as seen in the video above, does not have this problem.
Added "Extra Large" as an option for dual tube, unfortunately to my surprise it doesn't actually bring the cost down per tube at all!