Lower parts kits for your AR-15 or AR-10 build normally include parts such as the safety selector, pivot pins, springs, pins, and even occasionally will include parts such as your grip and trigger assembly. The lower parts kit (LPK) is one of the most important parts of any AR build. The LPK includes all the parts necessary to chamber a round, flip the safety, squeeze the trigger, and fire a round downrange using your AR-15 lower. When you pick out one of the AR15 Lower Parts we carry, for example, one of the Aero Precision AR15 Lower Parts, you’ll get precisely what you’re expecting. But we strive to provide more than just awesome products and super low prices. We appreciate that a lot of the equipment in our store calls for some amount of practical experience to properly evaluate and understand.