Messenger bag is 12"L x 11.5"W x 5" deep and has an adjustable padded nylon strap. It comes with an outside cell phone holder, 2 zippered pockets, one under the flap and one on the back. The inside is fabric lined, with two pockets, and a number of pen and pencil sleeves. The outside is made from heavy water resistant 600D nylon. The 12"L X 11.5"W interchangeable flap is made from a heavy weight canvas with polyester front. The flap on the small bag locks down with velcro pads.