Starr Arms Co. manufactured approximately 20,601 of these carbines during the Civil War, according to "Flayderman's Guide" (9th Edition, 9B-098). Features standard blade front and two-leaf rear sights, and a sling ring mounted on the left of the receiver. "499" marked on the left of the breech block, underneath the barrel, and rear surface of the forend. No U.S. inspection markings present on this example.