The Comp S/S Run Top is designed for supreme comfort to keep the wearer cool and dry through the most rigorous workouts. Providing ultimate moisture management, this top features four SMD fabrics and supreme anatomical engineering. SMD is an exclusive fabric to 2XU. With SMD Technology a low denier ( high filament ) yarn on the outside draws moisture through from the high denier ( low filament ) yarn on the inside. In addition, the inside yarn transports water through a capillary action. This combination multiplies the moisture management performance, keeping you comfortable and exceptionally dry. Add in zoned panelling and you have the ultimate, high performance, climate controlled athletic garment!