This bulkhead suits 4" fiberglass coupler. Has provision for a 3pin and 4pin JST XH connector for providing battery charging. Also provision for an o-ring to seal ejection charges from getting past.
This one was printed in resin on a Formlab 2.
Watch out for dimensional changes...
Didn't see a post about this (not that the search function would have found it) so I thought I would ask.
Went to assemble a CTI M2045 Blue Streak (6 gr) at our club launch two weeks ago and all the grain spacer O-rings were the wrong size. Someone on the assembly line had mistakenly packaged...