The graduated compression of the CEP Progressive Night Running Socks promotes blood flow and nutrient delivery speeding recovery time and reducing fatigue Reflective details add visibility for running at dusk and at night CEP Running Socks are also anti microbial to resist odor buildup Padding through the foot and around the Achilles adds extra comfort for long runs 85pct nylon/ 15pct spandex fabric Reflective details for added visibility Graduated compression promotes better blood return Enhanced blood flow for greater nutrient delivery Reduces muscle fatigue and recovery time Padding through foot and around Achilles for comfort Anti microbial treatment to prevent odor buildup Flat toe seams to prevent pressure points Breathable and moisture wicking to keep feet dry