Our Advanced messenger bags feature the ArkivA(R) closure system and are made with three different fabric variations: High Tenacity HT500, MultiCam Black Cordura, and 10 oz. American-made waxed canvas. Each bag is lined with a lightweight urethane coated ripstop liner.The addition of a double urethane coating on the fabric's face gives the bag extra structure and allows the bag to patina and naturally distress with age. The combination of a double urethane coating and our patented ArkivA(R) closure system results in an exceptionally durable and beautifully constructed barrier to the elements.The AP Series messenger bags feature a weatherproof roll top main compartment which can be used in either the "roll top" mode, or in the traditional "flap down" configuration and include quick-access outboard pockets, internal zippered pockets, custom aluminum strap hardware, and detachable cross-chest stabilizer.