2XU Men's Swimmers Compression Long Sleeve Top lycra-blend Imported Supports and protects shoulders, deltoids, back and core muscle groups Muscle Containment for reduced vibration and oscillation, less muscle fatigue and damage Graduated compression fit for increased circulation and faster recovery with a powermesh chest and back panels for breathability and flexibility. Certified 105 Denier Invista LYCRA Compression with a 360 degree fabric knit construction for a consistent yet powerful pressure Lightweight and breathable fabric with SPF 50+ sun protection for all day comfort