Based on designs by Joseph Peklicz in the #352 issue of the Apogee Peak of Flight newsletter. It’s a spool rocket with half pieces of tubing inducing a horizontal spin on recovery. Mine is designed so it can be flown clustered: there’s a central 24 mm motor tube with three 18 mm motor tubes arranged around it. No particular reason, just felt like it. Further from the center are the three half 24 mm tubes, and there are three 18 mm posts.