Rep your squad while they're hard at work on the gridiron with this San Francisco 49ers 2025 Sideline 39THIRTY Flex Hat from New Era. As the 2025 on-field cap of the Nfl Sideline, this lid is worn by San Francisco 49ers players, coaches and staff The 39THIRTY is New Era's premier stretch-fit style, engineered specifically to create a comfortable fit, and is designed with a quick-dry cushion sweatband that provides a soft, comfortable feel. The sewn-down silicone patch on the crown and a structured fit gives this San Francisco 49ers cap a premium look that you'll be proud to sport.