The Mega Arms GTR-3H Billet Ambidextrous AR-15 Receiver Set is what you need for your next premium AR-15 build. The upper and lower are fully machined from a billet of 7075-T6 aluminum and hardcoat anodized black to better than military specifications for longer term corrosion resistance. The stripped lower receiver features an integral trigger guard and a built-in ambidextrous bolt release. The magazine well features a flare for faster magazine changes and the front is textured for a better magwell grip.Features: 7075-T6 aluminum billet Matched receiver set Hardcoat anodized matte black Ambidextrous bolt release Integral trigger guard Flared magwell Mil-Spec parts compatible