Under Armour Socks: These take your sock set to the next level by being lightweight and breathable, yet still providing arch support Under Armour technologies: mesh panels in the forefoot for breathability Built-in arch support reduces foot fatigue Heel adjusts around the foot for a better fit SPECIFICATIONS The non-slip silicone inner grips on the back of the heel help prevent the socks from sliding down. Comfort front tongue protects the top of the foot against sting and cord irritation. PREMIUM MATERIALS - Material wicks sweat & dries really fast. 100% Polyester