SKINS Men's Bio Snow Thermal 3/4 Tights Nylon 73% / Spandex 27% Imported 76% Hollow Core Nylon, 24% Spandex Hollow-core nylon fabric offers 190% higher thermal rating and superior moisture wicking properties. Turbo charge your legs. Increased delivery of oxygen-rich blood allows you to ski/ride harder for longer and recover faster. Cold machine wash, gentle cycle, with like colors. Do not bleach, iron, or tumble dry.