With a 5-inch barrel made of Chrome Moly Vanadium and a twist rate of 1-7, the 5.56 NATO AR-15 Upper from Andro Corp Industries offers dependable performance. It comes fitted with a sleek M-LOK hand guard, allowing for easy customization with your favorite accessories. Constructed from Mil-Spec 7075 T6 aluminum and featuring T-marks, the upper is also dry film lubricated to ward off corrosion. Its use of Mil-Spec components makes it a trustworthy choice. BARREL SPECIFICATIONS: – Caliber 5.56 – Length 5" – Material 4150 Chrome Moly Vanadium – Profile Medium