The United States Navy, Coast Guard, and Marine Corps all use a single silver bar to indicate the rank of Chief Warrant Officer 3 (W-3 pay grade), but the Marine Corps sets it upon a red background while the seafaring services use a blue setting.
Both the Navy and Coast Guard employ pin-on metal rank insignia for outwear garments; in the Navy these comprise the Blue All-Weather Coat (Single- and Double-Breasted) and the Black Jacket, while the Coast Guard uses them on the Trench Coat and the Windbreaker. Wear instructions are the same both services, with the device placed so that its outer edge is 3/4-inch from the end of the shoulder strap or epaulet. Just as with bar-shaped insignia worn by junior officers (ENS, LTJG, LT, LCDR) , the CWO 3 insignia is positioned so that its long axis forms a fore and aft line.
Note that the Navy is phasing out the Single-Breasted All-Weather Coat, with a mandatory ownership date of 1 October 2020 for the Double-Breasted version. Black Jackets must be worn with the zipper closing the jacket at least 3/4ths of the way. Coast Guard regulations call for the Windbreaker to be zipped down to between 3 and 4 inches from the top and the zipper tab laid flat against the zipper.