White Shirt worn with the Service Dress Blue uniform. This shirt is worn with a tie and soft shoulder marks. No ribbons, or breast insignia on the shirt. Ribbons and breast insignia go on the navy dress blue Jacket. To determine your size, just measure your neck size (convert to inch if you are in a centimeter based country). The sleeve length is the second part of the description. So if your neck size is 16 inches, and the sleeve length is 34 inches, you should select size 16 * 34.