Runderwear Men's Briefs | Chafe-Free, Performance Underwear with Seamless Technology Polyester The Original Performance Underwear for runners and athletes across the globe Award-winning, chafe-free underwear with seamless technology for ultimate comfort and performance Lightweight, breathable and moisture-wicking technical fabric - 92% Polyamide, 8% Elastane Ergonomic, tag-free design with micro-perforations to improve core temperature control Non-fading, colour retaining and durable fabric for long lasting performance