Secrets of the Pros: Many of SIDI"s sponsored pros specifically request the SIDI Eleven Carbon/Composite sole because of its perfect balance of comfort, light weight and power transfer-it"s slightly less stiff, for more comfort on long days without sacrificing ultimate power. And it"s the foundation for the NEW FIVE, pairing the Eleven sole with SIDI"s beloved upper technology: Caliper Buckle two-way ratchet closure, SIDI"s no-slip High Security Velcro® straps and, above all, SIDI"s trademark fit, and the comfort that comes with it-extending from perfectly formed toe box to SIDI heel cup.