Micro crew height sits just above ankle bone. 100% NanoGLIDE extremely hydrophobic, durable and anti-friction fibers eliminate bulk for unprecedented dry, friction-free comfort. Microchannels increase airflow for maximum breathability. Ventilation over foot and at arch keeps feet cool. Elasticated arch offers extra support. 51% Merino wool, 27% nylon, 20% NanoGlide nylon, 2% Lycra Spandex.