Simms Guide Guard Wading SocksIdeal for days when waders aren't necessary, the Guide Guard socks provide comfort and warmth inside of Simms wading boots Constructed using 3. 5mm abrasion resistant neoprene in the upper and gravel guard, and perforated 3. 5mm neoprene underfoot for drainage Anatomically correct left and right patterning for superb fit and easy don doff Fold down gravel guard includes boot hook for security Unisex sizing: XS (M's 4 5, W's 6 7) S (M's 6 7, W's 8 9) M