This 500-45FS10B black fluoropolymer finish ETM magazine offers you the highest capacity and most reliable performance for your Full-Size .45 ACP 1911 handgun. Features: Caliber: .45 ACP Capacity: 10 rounds 1911 Size: Full size Black fluoropolymer finish Increased reliability in all 1911 pistols Aircraft grade certified stainless steel tube resists corrosion Strongest tube developed preventing cracked feed lips and tube spreading .025" tube walls Refined radius for each bend in the tube to take advantage of the strength in the stainless steel Proprietary custom designed welding process Multi-step tumbling and finishing process provides smooth follower operation and insertion into the weapon Observation slots moved to the rear of the tube exactly where they need to be to maintain the structural integrity required Innovative follower design with extended skirt ensures stability in operation and minimizes creep from the tube when your magazine is empty Fiber filled nylon follower The ETM seats and locks in the weapon with the slide forward