This is a great little button! It is the 18mm button for the 9th Infantry regiment. This is the style that is has the large number "9" in the center of the button. They also have the distinctive French style "turret" shank. This one still has the original shank on the reverse. In Don Troiani's book on Revolutionary War button this pattern is listed as F9.d. He tells that this stands for the Auvergne Regiments. In 1775-1776, the unit was at Martinique and then became the 18th Regiment Gatinois. Then the number was assumed by the Normadie Regiment on May 31st 1776. The One in the book was recovered at Yorktown, Virginia. It will enhance any Revolutionary War artifact collection.