I/O Bio Men's Merino Wool Contact Tight 96% merino/ 4% Elastane Imported 96% Merino Wool; 4% Elastine Manages moisture, insulates when wet, and dries quickly Natural Fiber. Naturally anti-microbial and anti-bacterial, I/O's merino fiber creates a robust fabric that survives years of wear & tear Seamless on the back and smooth seams for sliding into ski boots Fiji