This is a hat silk for the professional look. The LeMieux Pro Mesh Hat Silk is quartered with strategically placed mesh inserts. Not only for breathability this also prevents hat vents from being blocked. It is made from a silky smooth 4-way stretch fabric designed to fit over most helmet sizes. Makes a snug & secure crease free fit. All the Pro Mesh Hat Silks are finished with a signature LeMieux top stud.