Below is a style from HEADS Co. blending a little British earflap cap with 3-panel construction and full stretch fit. This version is made with heavy cotton jersey and weaved plaid fabric for the top crown. The hat features a double layered short visor and inner cotton lining. Real low key, this is a good, form-fitting cap for any chill out occasion. Not much info on availability but you can check casual / fashion headwear shops such as Arth or Urban Outfitters. 
©2009 Universal Article