An HPR fin attachment technique which provides much greater strength than t' typical surface mount used in model rocketry. T' use TTW, slots are cut in t' body tube where t' fins mount and t' fins are built with extended tabs on t' root edge which fit through these slots. In one form o' TTW, t' tabs are short and just provide a surface t' build up epoxy fillets on t' inside as well as t' outside. In a stronger version o' TTW, t' tabs reach all t' way t' t' motor tube where they are glued formin' a very rigid box structure (also known as TTW-GTMT for "Glued T' t' Motor Tube).