With an ultra-lightweight fit and breathable fabric, the Nike Challenger Running T-Shirt is designed for endurance and to keep you cool during hard work. Nike Dri-Fit - is an innovative fabric technology designed for great moisture management Considered Design - for high performance and low environmental impact Mesh crew neck - keeps your neck cool and dry whilst exercising. Allover flat-back mesh design - again, to keep air pasing through, keeping you cool and dry. Reflective Swoosh design trademark at left sleeve to help visibility in low light. Flat Seam Construction - Reduces chaffing and increases comfort What is Nike Dri-Fit? Nike Dri-Fit is a high performance, microfibre, polyester fabric which has the properties and build quality to wick sweat away from your body and move it to the surface of the fabric, where it evaporates; as a result, Dri-FIT fabric helps you stay dry and comfortable.