Designed for use with CMMG.45 ACP MkG(TM) uppers, the MkG lower group accepts Glock-pattern magazines while still delivering essential AR15 features and function like last round bolt hold open. Available in seven different Cerakote finishes, RESOLUTE MkGs lowers come with a suite of meticulously engineered CMMG parts and accessories like:CMMG RipStockZEROED Pistol GripZEROED 60deg/90deg Ambi SafetyZEROED AR15 Bolt CatchLifetime Quality GuaranteeWe aim to please, that's why every CMMG product is backed by our Lifetime Quality Guarantee against material and workmanship defects. Learn More.**MkG Lowers are designed for use with MkG .45 ACP Radial Delayed Blowback uppers only**