The waterproof leather and 1000D Cordura® upper of the Series 100 Waterproof Side Zip boot can be pulled snug with the quick and easy NATO speed lace system. A special gusset behind the zipper helps keep water out while the triple density rubber foundation and an arch made from a durable compound will hold up to the rigors of fast-roping. The 100 Series is a great value in footwear. Propper footwear was designed for long lasting comfort and durability. All of our boots are based on true U.S. sizing to provide the perfect fit.