3D printed in PLA in segments.  T' segments screw together t' allow makin' changes in t' rocket setup. Begad!  Designed for 18mm motors with a small air pocket around t' motor (ID o' tube is 22mm).  T' boat tail and engine block with flanges hold t' motor in place.  T' nose cone (elliptical) and payload bay are a single piece with a screw in cap for attachin' recovery device and shock cord. Avast, me proud beauty!