This Model Works Because You Put The Longer Part Of The Straw Into The Rocket And Then Simply Blow Into The Straw And Watch It Fly. Your Gonna Want The Rocket To Be Less Likely To Break, So It Would Be Best If You Used Either PETG or TPU To Print The Rocket. Although, You're Gonna Want The Straw To Be Stiff, So PLA or PETG Would Be Best For That.