The ASPIRE is engineered with firm compression and a thin profile for a responsive feel. Firm compression supports every contour of the foot to reduce fatigue during endurance activities. The Four height sits below the calf and it's double-cuff construction provides extra support for cycling and trail running. Thin profile is designed to fit into any technical shoe with a barely-there feel. Firmly hugs the contours of your feet to support the arch and help reduce fatigue. Built to provide maximum breathability with signature fibers that wick-moisture, keeping your feet cool, dry, and blister-free.