Like AC for your head.Protect the top of your head from vent-shaped sunburns with the Giro SPF Ultralight Cap. With a UPF30 rating, it blocks harmful UV rays. That's in addition to being light and airy — perfect for keeping your head cool under your helmet. It's a one-size affair, with an elastic rear panel to accommodate a range of head shapes and sizes. And since it's built from a blend of Power Mesh and antimicrobial X-Static fabric, it'll stay fresh between washes.The Giro SPF Ultralight Cap is available in one size and in the color White.