Marine Corps Master Gunnery Sergeant Rank Finish Pin is the official United States Marine Corps pin for enlisted Master Gunnery Sergeants. Master Gunnery Sergeant is the 9th rank enlisted officer in the United States Marine Corps. They are technical managers that oversee training and equipment over multiple troops and platoons. This is an official issue and is ready to be worn on an official United States Marine Corps uniform. This gold finish pin measures at ⅞ inches and is made in the USA.