Socks can make or break an outfit, and it is easy to see that the clean, contemporary styling of the Pro SL Sock II will be a welcome addition for even the most discerning wearer. These socks certainly aren't style over substance however. Fine Meryl fibers create a soft to touch, breathable sock that is also resistant to wind and rain. The Pro SL Sock II utilizes Meryl fabric containing particularly fine fibers, producing a lightweight fabric characterized by soft handle, breathability and resistance to wind and rain.