Very light and quick-drying ArmourDry technology improves performance.It disperses moisture evenly, allowing sweat to evaporate faster for a lighter, drier, cooler run.Energy Return cushioning for added protection in high-impact areas without bulk.The Locked-in Fit construction keeps the sock securely on the heel, so it doesn't need to be adjusted and won't fall off.The seamless toe provides excellent comfort and reduces irritation.The anti-odor technology reduces odor in the sock.Specific cut and design for left/right side.