This product is made with 100% recycled polyester fibers. Park First Layer Jersey provides coverage that won't cut down your speed. Dri-FIT technology helps you stay dry, comfortable and focused. Stretchy fabric with a smooth face provides a low-friction underlayer. Invisible Thumb Loops stay hidden when not in use. Raglan sleeves eliminate the shoulder seam to help you move freely. Swoosh design trademark is heat transferred on the center of the chest.