KAK Industries Parts Kit without Fire Control Group - Mil-Spec AR-15 Lower Parts Kit (US-Made) This KAK Industries lower parts kit provides all mil-spec components required to complete an AR-15 lower receiver, excluding the fire control group. It allows builders to pair the kit with a trigger pack of their choice for a customized setup. All components are precision-manufactured in the USA to meet mil-spec dimensions, ensuring a consistent and reliable fit with standard AR-15 lowers. The kit includes bolt catch, magazine catch, magazine catch button, takedown and pivot pins, detents, selector, pistol grip hardware, castle nut, endplate, buffer retainer and spring, and other standard lower receiver hardware. *Note: This kit does not include hammer, hammer spring, trigger, trigger spring, disconnector, disconnector spring, hammer pin, or trigger pin.*