Red Sox Fly Swatter Franchise Fitted Hat. This hat has a navy relaxed fit front panel, a mesh back and with a raised embroidery B, this hat is 100% garment washed cotton for a broken-in look and feel. This hat is perfect for summer, it has the classic look on the front and cool mesh back for a little air in the back. 100% cotton twill and soft mesh. This is a fitted cap, please see the size chart.