Nautical Signal Flag of Letter "U" in Shadowbox Frame

International maritime signal flag of letter 'U' set into a shadowbox frame. The cotton flag has a white canvas hoist with a sisal rope and wood toggle, with a maker's label from flag maker "Annin". The oldest flag maker in the United States and known for high quality and durability. The cotton field is red and white. The flag is mounted on beige matting, which is attached to a plywood backboard and placed in a shadowbox frame. The signal for the 'U' flag, when raised alone, is 'Anchoring, mooring, and weighing in the U.S. and international waters, the flag signals "You are running into danger." Very high quality framing. 19"H x 23"W