These are projects that the kids made, Tad had a plastic canister from something... And with aluminum foil, foam, glue and a empty grain box he created something, what would you call that? Nathalie used an empty packing box and some other bits of cardboard that she found. They each had an empty elastic roll of mine, these are the wheels. Tad was very certain that if these "projects" were tied to the back of the bicycle and one rode SUPER fast, the project at hand would take off and fly. Then one could cut it loose with a (dull) pocket knife and it would just soar! He was disappointed, Nathalie like the bump bump noise hers made when attached to the bike.