CMMG Inc Lower Parts Kit MK3 Gunbuilder's kit. Building on the mil-spec standard CMMG Gunbuilder's Kits include everything you need in a new or custom lower build where you add the trigger pistol grip and trigger guard of your choosing. Basic parts list: takedown pin safety selector bolt catch receiver pivot pin selector detent bolt catch plunger takedown pin detent (2) magazine catch bolt catch spring takedown pin detent spring (2) magazine catch spring bolt catch screw hammer and trigger pin (2) magazine release button buffer retainer and buffer retainer spring. Specifications for CMMG Inc MK3 Lower Parts Kit: Manufacturer: CMMG Color: Black Finish: Black Gun Model: CMMG Mk3 Condition: New Package Contents: CMMG Inc MK3 Lower Parts Kit The CMMG Inc Gunbuilder's Lower Parts Kit - MK3 38CA61A is a quality addition to the CMMG lineup. For more great deals on AR15 Lower Parts by CMMG please browse our CMMG Inc Gun Parts page. CMMG Inc Gunbuilder's Lower Parts Kit - MK3