Under Armour HeatGear Flyweight Run Split Short 100% Polyester Ultra-Lightweight Woven Fabric - Wont hold you down, but remains durable for heavy wear. Mesh Internal Liner - Helps moisture escape, keeping you cool and dry. 360 Degree Reflective Details - For keeping you safe in low light conditions. Regular Fit - Design to sit loosely on the skin. Side Pockets - Side pockets for essential storage and a Media pocket to hold a media device.