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