Product DescriptionThe Spikes ST-15 Complete Upper is a Mil-Spec compliant AR-15 upper assembly built for shooters who want dependable performance, durable materials, and a ready-to-install configuration. Chambered in 5.56x45mm NATO, this complete upper features a 16-inch cold hammer forged barrel with a black phosphate finish, a mid-length gas system, and a forged 7075-T6 aluminum receiver for strength and long service life. Its free-floating 12-inch handguard helps support consistent accuracy while providing ample space for accessories, and the included A2 flash hider delivers a proven muzzle setup. Designed to fit AR-15 platforms, this optic-ready upper is a strong choice for range use, training, and duty-style rifle builds.Product Highlights Complete AR-15 upper assembly chambered in 5.56x45mm NATO for reliable performance and broad ammunition compatibility. 16-inch cold hammer forged barrel with black phosphate finish and 1:7 twist rate for durability and stabilization of a wide range of bullet weights. Mid-length gas system with micro or low-profile gas block configuration helps promote smooth cycling and balanced recoil impulse. Forged 7075-T6 aluminum upper receiver provides lightweight strength for hard use and long-term durability. 12-inch free-floating handguard and A2 flash hider create a practical, optic-ready setup for modern AR-15 builds. Specs Brand: Spikes Model: ST-15 Complete Upper Manufacturer Part Number: STU5435R2S UPC: 815648023331 Caliber: 5.56x45mm NATO Compatible Platform: AR-15 Type: Complete Upper Barrel Length: 16 in Barrel Finish: Black Phosphate Barrel Construction: Cold hammer forged, Mil-Spec Barrel Profile: ST Optimum Profile Twist Rate: 1:7 Gas System: Mid-length Gas Block: ST Micro Gas Block Gas Seat Diameter: .750 in Receiver Material: 7075-T6 Aluminum Receiver Finish: Black Handguard: 12 in free-floating handguard Muzzle Device: A2 Flash Hider Thread Pattern: 1/2x28 Bolt Carrier Group: Spike&';s Tactical Mil-Spec M16 Bolt Carrier Group Sights: Optic Ready Weight: 4 lbs Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer.