Tailored to the features of male anatomy and optimized for the requirements of road cycling Rearward positioned and anatomically adapted pressure relief channel prevents discomfort and numbness SR Pro Carbon: Carbon composite shell with orthopedic AirCell foam with OrthoCell pads SR Pro: Nylon composite shell with orthopedic AirCell foam with OrthoCell pads SR Comp: Nylon composite shell with orthopedic comfort foam with OrthoCell pads Integrated Topeak Quickclick saddle bag mount Recommended sizing for sit bone width: S/M 912cm, M/L 12-16cm