During the summer of 2015 Claude asked me to help at a build session for foreign high school students. We used Flis Thingamajigs and Whatsamacallit. It worked out great. Both those kits use the Flis patented interlocking fins. One of the kits use streamer and the other a chute. I prefer a chute unless you are launching at a small field. Flis kits come with excellent directions. We used B6-4 engines which you can buy in bulk. We launched at the Acton field. Check out my latest Torrent post.