FITEXTREME Mens Sports Light Compression Base Layer Top Short Sleeve Nylon 82% Polyurethane 18% Ideal Performance for Sports and Outdoor Training, Made of Cool Extreme Fabric for Excellent Cool Touch, Polyurethane 18% of Composition for High Stretch, Provides you Great Freedom of Movement during Training 4 Way stretch Fabrication (Polyurethane 18% of Composition) allows Great Mobility in any direction, Keeps you Comfortable with High Stretch, Quick Sweat absorption and Flash drying, Helping you Stay Fresh and Dry Extreme Thin construction increase Cool Touch and bolster Extreme Fit tightly, Light weight and Extreme Thin make you feel like your second skin, Flat seams and Label printing for Minimizing Skin irritation and Chafing Maximize muscle stability, Work out for longer and Stronger, Promotes blood circulation for Training, and helps to reduce Fatigue Please refer to Actual Size Chart photo on the left product pictures, If you prefer a looser fit, Please Go up a size, FITEXTREME is officially registered Trade mark (Reg. No. 5337089 US PTO), FITEXTREME is sole official Seller who sell FITEXTREME Brand item