This shirt is made exactly the same as the baseball undershirts professional ballplayers wore in the 1950s and 1960s. The outer layer is made of an unbelievably soft blend of merino wool, cotton and nylon. The aerated cotton inner layer provides comfort and absorbs moisture. Our navy or oatmeal heather fungos will match any EFF authentic flannel jersey, or wear this rugged shirt alone for work or play! Choose your favorite team, with sewn felt letters, or buy 'em blank.