X-Bionic Energizer Medium Length Pant
Here's what other sites are saying:
The X-Bionic MenAAAs Energizer Medium Length Pant regulates your body temperature so that you are never over-chilled by your own sweat. Using the 3D-Bionic Sphere System, the Energizer diffuses sweat you produce so that your temperature stays at a steady level. When you donAAAt sweat, the system takes air heated by your body for thermal insulation. Expansion ribs on the knees store warm air inside and donAAAt lose heat when they bend. Since sweat accumulates behind the knees, X-Bionic created a fine knitted mesh to pull that moisture away from the skin without impeding knee movement.