These caps are a 5 panel seamless foam front with cotton lining behind foam and cotton sweatband to help you stay cool! These have a high crownheight of 4in and snap closure. OSFM. Supports adult hat sizes 6 - 7 1/2 or circumference measurements of 20in - 23 1/2in. Youth hats size circumference measures approximately of 17.5-20.5in with a 3in crown.