Zamberlan Hydrobloc full-grain leather uppers Microtex wicking nylon collar linings help control excess moisture around the ankle Gore-Tex Performance Comfort membranes guarantee waterproof and breathable protection for the life of the boot The proprietary Zamberlan Vibram 3D outsole with PU midsoles make for unique and unparalleled fit and performance. The ZFS (Zamberlan Flex System) allows the boot to very comfortably flex forward without compromising lateral support