The AERO Gen 2 stripped lower receiver is the perfect base for your custom AR-15 build. Machined to mil-spec dimensions, Aero lowers work with standard AR-15 components and ensure the highest quality with a correct component interface. The Gen 2 has improvements such as nylon tension screws that allow for a tighter fir between the upper and the lower. The Magwell size has also been increased for easier insertion of magazines and a sleeker look. The lower is machined from 7075-T6 forged aluminum and has a black anodized finish.