The CW-X Insulator Stabilyx Running Tights for men features: Insulator Stabilyx Tights use Auto-Sensor(R) nanotechnology fabric to maintain a constant comfortable surface temperature in a variety of conditions perfect for the cold weather athlete Patented Support Web bands together the muscles and ligaments of the lower leg to stabilize the knee and reduce vibration for increased efficiency Support Web also harnesses the midsection, supporting the lower abdominals, hips and back to channel power through the core Variable compression facilitates circulation during and after activity, minimizing lactic acid build-up so that you can be active longer and recover faster