When I printed this bottle rocket fin set, I found that the opening was 1mm too small for my bottle rockets, which measured right at 6mm in diameter. So, to go along with my nose cone, I give you this fin set - with a slightly larger opening. I also increased the thickness of the fins ever so slightly, since the original fins broke when I tried to remove them from the build plate. ! Have fun and Never Forget 1776 ! Print Settings Supports: No Resolution: 0.3 Infill: 100%