Ed Brown Mainspring Housings are fully machined from solid steel. The vertical serrations are machine cut into each housing to provide added purchase for wet or gloved hands. The arched design fills the hand and provides a different feel from the classic flat housing. The included magwell attaches to the bottom of the housing to allow easy removal without disassembling the 1911. The two piece design allows the firearm to be used in the standard mode, or with the maxi-well attached to facilitate faster magazine changes. No modifications to the grips are necessary.