I have brand new Mega Machine Shop stripped lower receivers available with consecutive serial numbers. These are 7075-T6 Aluminum Forging true black anodized lowers. Beautiful lowers for anyone wanting to build their own AR platform. These are stamped as "Multi" caliber and can be used for anything from 9mm up to 6.8 SPC magazines. Use them for a pistol or rifle build. Great lowers and they are instock ready to ship out.