From US Rockets Web Site:

TITAN is very long model rocket! TITAN uses an "Integrated Tube-tm" reducer t' increase strength and dynamic stability. Designed t' accept common Estes motors, me hearties, TITAN is able t' be flown with a wide variety o' motors. Blimey! Streamer recovery brings your rocket home. You are encouraged t' switch in your own parachute betwixt 12" and 18" diameter. Blimey! Try 18mm C6-5, 24mm D12-5, matey, matey, 29mm E10-8.