Product Description The Spike&';s Tactical ST-15 LE complete upper assembly is built to be inspected, tested, and ready to drop onto a compatible AR-15 lower. It features a forged upper receiver paired with a 16-inch M4-profile barrel in 5.56 NATO/.223 Rem, and it includes a phosphate M16 complete bolt carrier group for a true complete-upper setup. A rail-style handguard provides ample accessory mounting space, while Mil-Spec-focused components and factory test firing help ensure dependable function. Product Highlights Complete, drop-in-ready upper assembly that is inspected, tested, and test fired for function 16" M4-profile 5.56 NATO/.223 Rem barrel with 1:7 twist for broad ammunition compatibility Includes phosphate-finished M16 complete bolt carrier group (BCG) Forged upper receiver with M4 feed-ramped barrel extension for reliable feeding Rail handguard system provides robust accessory mounting and handling control Specs Brand: Spike&';s Tactical Manufacturer Part Number: STU5025-R9S UPC: 815648021085 Platform: AR-15 upper assembly (complete) Caliber: 5.56x45mm NATO / .223 Remington Barrel Length: 16" Barrel Profile: M4 Twist Rate: 1:7 Gas System: Carbine length Handguard/Rail: 9" Black Free Float BAR2 Rail Muzzle Device: A2 flash hider Muzzle Thread: 1/2-28 Upper Receiver Type: Forged Upper Receiver Material: 7075-T6 aluminum Bolt Carrier Group: Phosphate M16 complete BCG (included) Approx. Weight: 4 lb 3 oz 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.