This Atlas Gunworks premium magazine features a stainless steel body with black base pad. Atlas recommends premium magazines for shooters looking for high performance, good looks, or both. From competition to carry, Atlas has you covered with the best magazine for most modular 1911 double stack or Staccato 2011 style pistols. Features: Caliber: 9mm Capacity: 21 Rounds Tube: 140mm Stainless Steel Follower: Lockback Spring: +18% Basepad: Black Anodized Aluminum Backed by the Atlas Magazine Warranty Classic Magazines Compability- All Atlas Gunworks Pistols with a tactical or carry magwell All known Staccato 2011 style and 1911 double stack modular pistols with no magwell or a Staccato Compatible Magwell Staccato*: Staccato C2, Staccato P, Staccato XL, Staccato XC using a Staccato Magwell Springfield: Prodigy 5" 1911 DS, Prodigy 4.24" 1911 DS *Some Staccato Pistols made after August of 2024 have new frame dimensions, which prevent the use of all known aftermarket magazines.