AR-15 80 % Lower Receiver 5 Pack. Each OX Armory lower is Precision machined from the highest grade Aircraft Aluminum Block. Our signature series includes an oversized trigger guard. The flared mag well proudly displays the OX icon that distinguishes our product from all others. Finally, our lower is presented in a durable flat black anodized finish (standard) but is also available as a tumbled aluminum billet unfinished. 80 lower 5 pack in stock.