These are Billet 7075 T6 aircraft grade aluminum lowers. Precision milling on a 5 axis CNC. The lowers are Mil-Spec and go through a major quality and control process to meet the standards of the weapon. We provide raw, tumbled and coatings for your selection. These lowers have a lifetime guarantee for manufacturing defects. The buffer tube is threaded and tapped. We even cut a guide to start your milling from the rear take down pin. The jigs are for the lowers we offer only. The magwell is milled to perfection and will accept PMAGS. The only remaining milling is the trigger group, safety selector switch and the trigger pin slots. Product is CNC machined raw aluminum, then media tumbled.