1" with no back paper or maker name. Metal back has slightly heavier than usual oxidation and the celluloid has light age marks on about 50%, a little heavier along the lower right rim edge. Pictured is "Gen Tsai Ting Kai/Commander 19th Route Army." He was responsible for holding off the Imperial Japanese Army during the Shanghai War of 1932. This button likely dates from the late 1930s when Japan again invaded China and he traveled to the United States attempting to gain support from Chinese Americans for the war effort. Only example we've seen. Still has full gloss. Rare.