Knex Rocket Car By knex man123456 in LivingLEGO & K'NEX2,2088Save PDFFavoriteIntroduction: Knex Rocket CarBy knex man123456Follow About: (\_/) TE-HE (o.o)TE-HE (><)TE-HE More About knex man123456 »this is my knex rocket car .to use you put a co2 cartridge in it a open when its in.