Heat-treated steel construction Corrosion-resistant blued finish Steel music wire spring All-steel follower The Auto OrdnanceA(R) M1 .30 Carbine 15-Round Magazine is a factory OEM centerfire rifle magazine, crafted from durable, heat-treated steel for unmatched reliability and combat-ready performance at an affordable price. Featuring a corrosion-resistant blued finish, while the welded steel base plate offers improved durability in harsh environments. The heavy-duty music wire spring offers long-lasting feeding performance and a positive slide stop operation for enhanced reliability, while the low-friction, controlled tilt steel follower ensures smooth feeding operation with virtually no risk of binding. Better yet, this magazine is machined to exact specifications for a consistent, wobble-free fit for added reliability. Founded by the inventor of the legendary Thompson submachine gun over a century ago, Auto Ordnance is dedicated to preserving the heritage of America's most legendary firearms-while continuing to innovate and improve in the pursuit of perfection. Enjoy superior field performance and consistent operation with this historical icon. So what are you waiting for? Order yours today!