The Spikes Tactical STU5435R2S Complete Upper delivers a ready-to-integrate 5.56x45mm NATO platform with a 16-inch Black Phosphate midlength barrel, precision-constructed from 7075-T6 aluminum with a Black receiver and a 12-inch SAR3 free-floating handguard designed for AR-15 compatibility. This assembly features a midlength cold hammer forged barrel delivering a balanced blend of reliability and soft recoil, paired with a 1:7 twist rate to stabilize a wide range of 5.56 ammunition while maintaining accuracy at practical rifle ranges. Optic-ready sights are not included, allowing you to mount your preferred optic or sights to suit your mission and shooting style, while the free-floating SAR3 handguard preserves barrel harmonics for improved consistency during rapid follow-up shots. The black-on-black finish scheme provides a sleek, low-reflective profile that complements most upper receivers, and the 7075-T6 aluminum construction offers a durable backbone for demanding field use, range sessions, or timely field repairs. Ideal for building a high-performance AR-15 platform, this complete upper streamlines assembly, enabling you to tailor your rifle to precision shooting, duty-style engagements, or versatile outdoor applications with reliability and modern modularity.