You could build some lower with plain old mil-spec style parts OR... you could build an AR15 lower that takes each part and piece a step above.Kit includes a ZEROED Gunbuilder's Lower Parts Kit along with:ZEROED 60deg/90deg Ambi Safety SelectorZEROED Ambi Mag Catch and Button KitZEROED AR15 Bolt CatchZEROED Trigger GuardStepping in place of a mil-spec trigger is the phenomenal TriggerTech AR-D two-stage trigger designed for DISSENT and AR15 firearms. With a total pull weight of 4 lbs, short travel, and clean crisp break, the AR-D trigger may just ruin you of wanting to use any other two-stage trigger again.