SIDI puts rider fit and performance foremost, and the results speak for themselves. Winning is SIDI's legacy, established by more than 50 years of footwear innovation in the pursuit of performance and helping athletes realize their fullest potential. SIDI - A continuing passion for craftsmanship. Replacement soles for all Sidi off-road boots with a sewn-on sole. The TA sole features more rear brake feel than the SRS sole due to the material aspects of the sewn-on sole construction. Nothing is sacrificed in quality or safety; any knowledgeable cobbler can replace the TA sole. Sold in pairs.