The highly functional X-SOCKS RUN RETINA 4.0 are just right for your long-distance runs. The Retina Ultra-High Definition technology not only makes these socks lighter and more comfortable but also allows for strategic combinations with our other technologies. The socks, produced with the utmost precision on state-of-the-art machines, feature an intricate knit construction made from extra-fine yarn, resulting in lighter and thinner running socks that are simultaneously extremely high-performing. The newly designed AirConditioning Channel 4.0 allows air to circulate along the soles of the feet, effectively cooling them. At the same time, the newly designed Lambertz-Nicholson Achilles tendon protector 4.0 safeguards the sensitive tendon area with cushioning on both sides against pressure, impacts, and friction. Additional protection in the heel and ankle areas is provided by the AirFlow Ankle Pads. AirConditioning Channel 4.0: 3D structures and technical specialty yarn enhance air circulation and thus foot ventilation. Instep protector with Airvent Zone: The 3D knitting technique prevents the socks from sticking to the feet. The result is improved ventilation and fewer blisters.