Get ready for the biggest San Francisco 49ers games of the season with this 2025 Rivalries Collection Sideline 39THIRTY Flex Hat from New Era. The 39THIRTY is a premier stretch-fit style, engineered specifically to create a comfortable fit, so you can celebrate every victory in style and comfort. The premium embroidered team graphics have raised details for a dimensional appearance that looks great and shows your loyalty to the San Francisco 49ers.