The Q-Jets are the world’s most advanced 18mm model rocket motors. They utilize a patent pending high-strength polymer case and bulkhead, ceramic nozzle and RCSs exclusive Black Max aerospace- grade composite propellant formulation, which produces nearly double the specific impulse (or “Isp”, a propellant efficiency rating) of conventional black powder propellant. They are not susceptible to thermal cycling like black powder motors. Q-Jets generate a highly-visible exhaust plume and delay smoke trail. All Q-Jets ship with a FirstFire Micro 2-lead igniter, which can be used with any launch controller. All Q-Jet motors are U.S. mailable with no hazmat fee! Motor Diameter: 0.703″ (18mm) Casing Length: 2.75″ (70mm) Total Impulse: 2.5 N-sec Burn Time: 0.82 seconds Average Thrust: 3 newtons Delay Time: 4 seconds Propellant Weight: 2.1 grams Motor Weight: 18.2 grams