"The Hybrid Ax/Rx long sleeve compression shirt is a Unisex Patented Design that features a combination of moisture wicking breathable DFND Ax fabric and powerful embedded inserts made of DFND Rx Fabric that enables the body to maintain a more balanced posture, enhance power out and decrease the possibility of injuries. The sleeves are constructed with graduated compression to help enhance blood flow and is part of our sleepwear recovery program when worn with the Recovery Compression Tight. Each garment is constructed with flatlock seams to help reduce chafing." Labeled as an XL but fits best for people who wear a medium or on the smaller side of large shirts. Never worn, military issued.