With the 4.0 Run Speed, you are always one step ahead and benefit from the increase in performance thanks to innovative technologies. With their optimally combined ventilation and protection functions, these socks from the X-Bionic 4.0 generation are perfect for medium and long-distance runs. Compared to the previous models, you can expect even more comfort and performance-enhancing precision. The developed Air-Conditioning Channel 4.0 is embedded in the tightly knitted material to ventilate the soles of the feet. The instep protector with extended Air Cool Stripes climatises the back of the foot and at the same time protects the instep from pressure and friction, while the Suppronation bandage over the back of the foot prevents overpronation or supination and stabilises the foot in its natural rolling motion. The comprehensive cushioning system also includes the high-performance AirFlow Ankle Pads 4.0 on the ankle and the shape-optimised Lambertz-Nicholson Achilles tendon protector 4.0 above the heel.