Keep the sun out of your eyes while you cheer on the Boston Celtics with this New Era Adventure Perform Vented 9SEVENTY Stretch-Snap Hat. The 9SEVENTY design provides a modern adjustable fit and versatile style with its structured crown and semi-curved visor. Breathable, perforated mid and rear panels work together with COOLERA technology and MICROERA technology to keep you feeling cool, dry, and fresh.