Fusion Pro-Series, Stainless steel Mainspring Housing, for Full Size Government size 1911 frames. CNC Machined from Steel Bar-Stock, With Plain/smooth back. Matte finished. Equipped with lanyard loop feature. Will fit most all 1911 full size 5 inch Government pistols and Commander size pistols and Clones. All CNC machined in the USA,. No MiM, No Cast, ALL Solid CNC Machined Bar-Stock. This is a high grade Premium Professional grade Gunsmithing part. These are Top Quality Fusion Professional Series Parts; Made from the best materials and processes available in today's market. This is one of our most popular hammers. Made in the USA.