Xerotherm Socks (UNISEX)The Fourth Element Xerotherm Socks are a perfect complement to the Xerotherm undersuit range, providing excellent thermal protection and comfort for the feet! They are made with flat locked stitching and a single layer high wicking fleece fabric to protect the extremities without adding too much bulk in fact they can be worn under other thermal socks without making drysuit boots feel too tight or uncomfortable.