If you are a shooter this is a must for your spare parts box. This Original Stirrup and Pin was used in all M1861, M1863, and M1864 Springfield .58 Caliber muskets, all model 1866-1870, 50-70 Caliber Springfield rifles and muskets, all Model 1873 -1888 45-70 Caliber Springfield, carbines, rifles, and cadet rifles. I