Pull’em up, Flip’em Down, walk on! Whether you’re on the trail, on the job, or in the yard, FlipSockz will keep Mother Nature out of your boots! Flipsockz eliminates dirt, grit, and debris from getting stuck in your boots. With Flipsockz’ innovative nylon sleeve attached, you will no longer need to worry about annoying debris getting trapped in your boots during the course of your day. The nylon sleeve simply flips down over any boot, preventing mother nature from getting trapped, keeping your feet comfortable. 62% Merino Wool 36% Nylon 2% Elastane U.S. Sizing: S/M: Men size 3 - 6 / Women size 4 - 7 M/L: Men size 6.5 - 10.5 / Women size 7.5 - 10 L/XL: Men size 11 - 12 / Women size 10.5 - 12.5 Works best with 3/4 boots Many fans say these fit somewhat big - expect some room.