Elevate your everyday look with the iconic New Era Diamondbacks 9FORTY A-Frame UPSD Arch Cap. Crafted from 100% polyester, this baseball cap maintains its shape even after long-term use and keeps you comfortable. Stay game-ready and back your team through every inning with the New Era Diamondbacks 9FORTY A-Frame UPSD Arch Cap. Part of the 9FORTY A-Frame Arched collection. 100% polyester.