Designed for superior reliability in stressful environments and self-defense applications, the ProMag® FNX-45 .45 ACP 20-Round Blued Steel Magazine features a rock-solid, blued steel body for long-lasting durability and corrosion resistance, while numbered witness holes deliver quick visual round counts for added convenience. The high-tensile steel spring and controlled-tilt polymer follower work together to ensure smooth, reliable feeding performance. Better yet, the polymer floorplate is easy to remove when maintenance and cleaning are required.