I'm selling this because I bought the wrong size. 3L I've tried it on once. Uses a special hollow-core polyester yarn. ● Traps body heat within the fibers, increasing warmth. ● The long, brushed fibers provide a double effect, warming the body. ● During exercise, the mesh structure of the fabric releases moisture. ● Softer and lighter than regular polyester, reducing stress during wear, and suitable as a mid-layer. ● FLY WARM is reversible. ・ Prioritize warmth: Wear the brushed side against the skin. ・ Prioritize style: Wear the brushed side outward. (Recommended for business settings when prioritizing style.) FLY WARM Reversible Long Sleeve Shirt JW-283