The Clean Up baseball cap is an unstructured or “relaxed” hat with a shallow crown and curved visor, plus an adjustable strap closure for a comfortable fit. Made from garment washed cotton twill. '47: Founded in 1947 with a souvenir cart outside Boston's Fenway Park, '47 creates authentic headwear and apparel that captures the spirit of the game. Adjustable strap at back. Men's One Size fits most.