The 5mm Xero Enduro from Billabong are very warm wetsuit boots with fluffy quick drying lining on the inside and sealed seams on the outside they're going to keep your feet warm throughout winter. The cuff at the top of the boots is the same as the Drylock boots from Xcel it creates a really effective seal which prevents water getting into the boot keeping you warmer. Drymax Cuff EZ-On Pull tab Furnace lining Non Marking grey gum sole Flex Cut Arch Durable Arch Bridge Internal Split Toe :: Men > Wetsuits. Crafted from 100% SuperStretch Neoprene for comfort and flexibilityTaped seams to avoid cold water from enteringOptimum flex and grip with thinner rubber outsoleRound toeExtra warmth with Furnace thermal liningAdjustable ankle strap5mm thicknessPull on heel strap for easy access Size: UK 4,UK 5,UK 6,UK 9,UK 3,UK 11,UK 12.