From our friends at Float Life:
"Whelp... I guess we wear helmets now, so you know we had to make the perfect hat to rock under your lid! Introducing the Under Helmet Hat (UHH) made specifically to go under your helmet. This hat is super lightweight, breathable, adjustable, flexible, water resistant and has minimal structure (never misshapen). And when it gets dirty just throw it in the wash because it's machine washable!!
Features: Nylon blend + Polyester mesh, soft flex visor, moisture wicking sweatband"