SRC .223 .223 Rem. / 5.56mm NATO Gas Impingement System. Ships with one 5 Round Magazine. Manual Lever with Indicator Markings on Both Sides of Receiver. M4A4 Type Flat Top Upper. Receiver Forged 7075 T6 Aircraft Aluminum. Hardcoat Black Anodize Finish. Carpenter 158 Steel 16” M4 Profile, Chrome Lined. 4150 Chrome Moly Vanadium 11595E Steel w. M4 Feed Ramps. 1 Turn in 9” - Right Hand Twist Hard Plastic Gun Case with Black Web Sling & Operators Manual. Transferable Lifetime Warranty.