No one's a bigger Arizona Diamondbacks fan than you, and that'll be clear when you rock this Mother's Day 39THIRTY Flex Hat from New Era. The crisp Arizona Diamondbacks graphics make this a unique addition to your collection and will help you stand out from fellow baseball fans. Whether you're headed to the field or watching from home, you'll let everyone know your allegiance lies with the Arizona Diamondbacks. Major League Baseball will donate its licensed royalties from the sales of such items to organizations supported by MLB Charities, including Susan G.