Castelli Men's Free Aero Race Short - 2015 Lycra Vortex dimpled fabric on legs for aero performance Forza fabric on inner legs with 38% Lycra content for perfect fit GiroAir mesh-like leg gripper elastic for better grip distributed over larger area Doppio V construction in front for increased support and comfort Flat-lock stitching Reflective detailing on back. New improved Progetto X2 Air seat pad