Mistral’s Twin Air Technology® in using 2 sepa-rate narrow chambers, sealed around the outer rails by a singular compression-band, limits both static and dynamic load affects in relation to flex. Past systems have included, side fitting battens, carbon stringers and turn-buckle assemblies, but have all failed to add true stiffness to accep-table levels of difference. In addition they often required more hardware, more weight and more inconvenience.