Aero’s Gen 2 stripped lower receiver is the perfect base for your custom AR-15 build. Machined to mil-spec dimensions this lower works with standard AR-15 components and ensure the highest quality with a correct component interface. Gen 2 improvements include nylon tipped tensioning set screw to fine tune the fit of the upper and lower receiver and an increased magwell flare easier insertion of magazines and a sleeker look. The rear takedown pin detent hole is threaded for a 4-40 set screw. This lower is made in America machined from 7075-T6 forged aluminum marked “Cal Multi”. NOTE: Requires a lower parts kit buffer & stock of your choosing to complete.