Montana Fly Company Boat BoxThe MFC Boat Box is a revolutionary totally waterproof fly box that was designed for use in boats, backpacks, or for travelling with large quantities of flies. One box that can cover any situation. Utilize large foam for big flies (size 8 and larger), or small foam for your smaller flies (size 10 and smaller). The center leaf should be added to double the capacity. The fly leaf is also available in either large or small foam.