Inspired by the success of the original MkG, the MkGs lower receiver is designed to accept either 9mm or .40 S&W Glock and SGM magazines. Features include an integrated trigger guard, last round bolt hold open, oversized magazine release, flared magwell, and multiple finish options. The MkGs lower receiver can utilize any AR-15 mil-spec Lower Parts Kit or Drop-in Trigger of choice, making the MkGs an incredibly customizable multi-caliber lower receiver.Each receiver is finished in your choice of one of seven premium Cerakote options.All CMMG products come with their Lifetime Quality Guarantee.**MkGs Lowers are designed to work with CMMG MkGs .40 S&W or 9mm Radial Delay Blowback Uppers only**