Fusion Firearms Mainspring Housing Alloy Gov Checkered Stainless. All CNC machined in the USA. No MiM No Cast ALL Solid CNC Machined Bar-Stock. You will not find better quality for your money Specifications for Fusion Firearms 1911 Mainspring Housing: Manufacturer: Fusion Firearms Gun Make: 1911 Platform Condition: New Package Contents: Fusion Firearms 1911 Mainspring Housing What firearm models does the manufacturer say Fusion Firearms 1911 Mainspring Housing is compatible with? The manufacturer says that Fusion Firearms 1911 Mainspring Housing is compatible with Colt 1911 Officer Colt 1911 Government 5in 1911Fusion Firearms 1911-MSH-27-18: 1911 Mainspring Housing Alloy Gov Checkered Stainless