MLB (Major League Baseball) Authentic Collection. On-Field uses the same materials as those worn by MLB players on the field, and the design is exactly the same. It uses high-performance materials with high breathability, sweat-wicking and quick-drying properties, and UV protection (UPF50+). ■Low Profile 59FIFTY The [Low Profile 59FIFTY] retains the basic features of New Era's signature style [59FIFTY] but has a lower crown design. It is characterized by its rounded form. The size is 7 3/8, which is 58.7cm. The team name is the Boston Red Sox.