These bayonets fits on the Model 1853 British Enfield 58 cal. musket. They resemble the 1855 Springfield bayonets, but they are more squared off next to the socket, where as the Springfield is more rounded and tapered. Also the Enfield’s have different Hallmarks on them as shown in the close up picture. The Springfield just has US stamped in it. One has to be careful, because a lot of people try to pass post war Enfield bayonets off as actual war time period ones. Learn your Hallmark stamps. As with the Springfield bayonets, I find these at various Civil War shows.