Xterra Wetsuits - Lava Booties - 2mm Neoprene Wetsuit Socks neoprene Surfers and paddle boarders on the cusp of two sizes can size up for a more comfortable fit Made of 2mm 4-way stretch neoprene, these booties are form fitting and insulating for cold water swims Flex panels on the top of the foot and above the heel allow for comfortable movement