We've adapted our most technically advanced sock, the Damascus, to create a lightweight performance sock - The Tropical. Made with 19.5 micron US merino wool on a 200 needle knitting machine, this sock provides the comfort of a thicker sock, but in a lightweight package. The Tropical is treated with No Fly Zone -A permethrin-based technology that may help prevent the spread of insect born diseases by repelling insects through apparel, uniforms, or gear.