This is an O class sugar rocket motor. The design is based on 4 BATES style grains. The motor is designed with a 2.5X safety margin, but we are still talking about 3000psi in the chamber. Materials are all 6061 except the nozzle is 1080 steel. EXPERT ROCKET BUILDERS ONLY! CLASS 3 LICENSE REQUIRED TO LAUNCH! Do your research before building! I am not responsible for any damage you do to yourself with this rocket! If you have any questions on this contact me.