The TRS Conceal-N-Carry Spy Cap with four secret pockets sewn into the extra think liner. The hat is constructed from tightly woven cotton poly-twill fabric. The structured bill is 3/8th inches thick - twice as thick as a regular ball cap. The hidden compartments are not visible from the outside or looking inside the hat. The opening for each pocket is 3-inches wide with a sturdy velcro strip that seals the pouch closed. Only flipping down the sweat band reveals the velcro openings. The hat has an adjustable velcro sizing strap, allowing this to fit on most heads.