Now you can proudly wear the insignia of the National Aeronautics and Space Administration thanks to the NASA Logo Black and Heather Gray Baseball Tee. With over fifty years devoted to the civilian space program and aerospace and aeronautics research, it's no wonder that NASA shirts are in such high demand! This baseball tee has 3/4 sleeves. Body: 50% Cotton, 50% Polyester. Sleeves: 100% Cotton.