Always stay one step ahead and benefit from the performance boost of innovative technologies with the X-SOCKS 4.0 RUN SPEED TWO MEN. With their optimally combined ventilating and protective functions, these X-BIONIC 4.0-generation socks are perfectly suited for medium- and long-distance races. Compared to previous models, you can expect even more comfort and performance-enhancing precision.The newly designed Air-Conditioning Channel 4.0 is embedded in the densely knit material to ventilate the soles of the feet. The Instep Protector with extended Air Cool Stripes provides air conditioning for the back of the foot and simultaneously protects the instep against pressure and friction, while the SUPPRONATION-BANDAGE over the anke inhibits over-pronation or -supination and stabilzes the foot in its natural rolling movement.The comprehensive cushioning system also includes the high-performance AirFlow Ankle Pads 4.0 at the ankle, the shape-optimized Lambertz-Nicholson Achilles Tendon Protector 4.0 above the heel.