Ed Brown Products Mainspring Housing Internals Government Stainless Steel. Includes mainspring (Government 19# Officers 23#) mainspring cap mainspring housing pin retainer and mainspring cap pin (blue and stainless). Note: the mainspring cap and mainspring housing pin retainer are stainless steel. Specifications for Ed Brown Products 1911 Mainspring Housing Internals: Manufacturer: Ed Brown Products Color: Stainless Steel Gun Make: Ed Brown Package Contents: Ed Brown Products 1911 Mainspring Housing Internals What firearm models does the manufacturer say Ed Brown Products 1911 Mainspring Housing Internals is compatible with? The manufacturer says that Ed Brown Products 1911 Mainspring Housing Internals is compatible with Colt 1911 Government 5in Colt 1911 OfficerEd Brown Products 814-INT: Mainspring Housing Internals Government Stainless Steel