Atmospheric Administration Commissioned Corps—the two small services, consisting only of officers, which are the two uniformed services that are not armed forces—wear uniforms and rank insignia adopted from the Navy. The combination covers of the two services are identical to those of the Navy with respect to colors, and peak ornamentation. The chinstrap of the PHS is gold with a burgundy stripe. The buttons securing the chin strap to the sides of the band are smaller versions of the buttons worn on the services' uniform coats. The cap device of NOAACC officers is similar to that of Navy officers with a globe in place of the shield; the cap device of PHSCC officers is similar to that of Navy officers but has a caduceus in place of one of the anchors. United States Maritime Service While the majority of American merchant mariners are employed by shipping businesses and accordingly wear either uniforms prescribed by their employers or civilian attire, some officers receive commissions in the United States Maritime Service for federal government duty, such as the faculty of the United States Merchant Marine Academy and the Military Sealift Command's civilian officers manning non-commissioned United States Naval Ships. These officers wear uniforms and rank insignia adopted from the U.S. Navy, albeit with United States Merchant Marine's own button design, cap device, awards, and decorations. The combination covers these officers are identical to those of naval officer with respect to colors, chinstrap and peak ornamentation. The buttons securing the chin strap to the sides of the band are smaller versions of the buttons worn on their coats. The USMS cap device is a rendering of the Merchant Marine device in gold- and silver-colored metal. Like the device worn by naval officers, it features a silver eagle, with wings outstretched, above a gold shield; the shield, however, is defaced with an anchor and surrounded by a wreath. Variants A typical peaked cap has a spring stiffening, often in the form of a wire grommet frame, to ensure the sides and rear of the fabric covering have the proper shape. A crusher cap removes the stiffener to allow headphones to be worn over the hat or use in confined spaces such as tanks and submarines, giving it a slouched and worn "crushed" appearance. Such modified caps were especially popular among US Army Air Forces combat pilots and German tank commanders and submariners in the