The CW-X Pro Tights unite the major joints of the leg to offer optimum muscular support for activities with linear movement, such as running and Nordic skiing. The patented CW-X Support WebTM brings the hips, knees and ankles into proper alignment, reducing impact and load to the legs. The CW-X Support WebTM also creates a suspension system for the hamstrings and quadriceps, reducing workload in both the pull and push phase of the running motion. Combined with targeted variable compression to increase circulation and reduce fatigue, your muscles don't have to work as hard over time and your legs will feel fresher. SIZES: S, M, L, XL.