Size Chart Description Performance air-jersey polyester material Full-profile, pro-model crown Flat visor Closed back Flexfit Pro-stitched finish Self-material undervisor Breathable Moisture wicking Dye lots can vary based on the manufacturer and garment material. Shades of caps may vary slightly from uniform. Size Chart Size: (Diameter) Youth: (6 3/8" to 6 7/8") S/M: (6 7/8" to 7 3/8") L/XL (7 3/8" to 8")