Each of the Revelry bags are built with custom system of layers. The outermost layer is a rubber-backed nylon. This material is woven for strength, and backed with rubber for two reasons: to protect the Activated Carbon Filter (ACF) from water damage, and to add an extra layer of odor protection. Working your way into the bag, there are two layers of ACF. These layers work together to filter out any unwanted odors. Lastly, they have a cotton lining. It is soft to the touch and also helps to protect the longevity of the ACF. These bags all have rubber-coated zippers, genuine leather accents, and metal hardware.