e4Hats.com Youth Conductor's Cap-Blue White 100% Cotton Made of 100% cotton. One size fits most with adjustable velcrorized strap, base is at 6 3/4, fitting from XS to M. Crown measres 4 inches deep, unconstructed, low profile, mesh lined inside. Bill measures 3 inches long, pre curved, same color under bill. Cool, light and soft material.