New Era"" and ""5950"" are the two names synonymous with baseball headwear. The 5950 On Field Authentic Collection Cap is the Official Cap of Major League Baseball. This Cap is worn by every MLB player on the field. Top of the line all wool 59/50 cap with Swiss embroidered official team insignia on the front. Official MLB logo on the back. Available in exact sizes 6-5/8 thru 7-3/4.