Estes Der Big Red Max Advanced Model Rocket Kit (29mm Engine) 9721This 3 inch diameter version will deliver the long slow lift offs that Red Max is famous for. Imagine 3. 5 seconds of smoke and fury on an Estes F15 4! And Big Red is not just fun on the flying field, hes fun to build too. Thru the wall fins make assembly and alignment easy while giving this rocket extra strength so you can fly it over and over. And only Red Max rockets come with their own special printed Skull & Bones 18 inch parachute. WHAT YOU NEED