All of Semroc's rocket kits are great but I really like their SLS series. The SLS Aero-Dart is modeled on the late 60s-early 70s Centuri/Enerjet Aero-Dart kit which was the third or fourth Centuri kit named Aero-Dart. The Semroc version has quality parts and is a solid build. I built mine to be flown at NARAM-49 where it turned in a great flight. .