SmartWool PhD Slopestyle Light Switch Alley-OOP Socks - Past Season Light Cushion: Light cushioned sole, shin and calf for impact absorption. PhD = Built for Performance in the Highest Degree. 4 Degree Elite Fit System: Uses two elastics for greater stretch and recovery to keep the sock in place. ReliaWool: Patented ReliaWool technology in high impact areas provides superior durability. Designed to celebrate the original socks with style. Flat knit durable toe seam Sock Height: Over the Calf - 14" overall height Knit in USA of Imported Yarn - Style: SW0SW326