Product Description The Spike&';s Tactical ST-15 LE complete upper assembly is built to Mil-Spec standards for dependable performance and easy drop-in installation on compatible M4/AR-style lowers. This complete upper features a 16-inch 5.56x45mm NATO barrel with an M4 profile, a carbine-length gas system, and an A2 flash hider for proven handling and reliability. It includes an F-marked A2 front sight base and durable M4 double heat shield handguards, along with a Mil-Spec M16 bolt carrier group for a ready-to-run setup. Product Highlights 16-inch 5.56x45mm NATO M4-profile barrel with Mil-Spec phosphate finish for durability Carbine-length gas system with F-marked A2 front sight base for classic M4 configuration 7075-T6 aluminum upper receiver for strength and long service life Includes Spike&';s Tactical Mil-Spec M16 bolt carrier group (BCG) for a complete upper assembly M4 double heat shield handguards and A2 flash hider for reliable handling and heat protection Specs Brand: Spikes Manufacturer Part Number: STU5025M4S UPC: 815648021030 Type: Complete upper assembly Caliber: 5.56x45mm NATO Barrel Length: 16 in Barrel Profile: M4 Twist Rate: 1:7 Gas System: Carbine length Barrel Finish: Black phosphate / Mil-Spec phosphate Upper Receiver Material: 7075-T6 aluminum Sight Base: F-marked A2 front sight base Handguard: M4 double heat shield handguards Muzzle Device: A2 flash hider Included: Mil-Spec M16 bolt carrier group (BCG) 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.