Springfield Armory Echelon 4.0C Magazine Engineered for precision, this 18-round extended magazine is designed for the Springfield Echelon Compact. Constructed of stainless steel, it features numbered witness holes for quick round count reference and a polymer base pad for faster tactical reloads. The blacked-out corrosion-resistant coating ensures long-lasting durability. Caliber: 9mm Luger Capacity: 18rd Firearm Fit: Springfield Echelon Compact Material: Stainless Steel