Wilson Combat has been supplying serious shooters and professionals with reliable and durable .45 auto magazines for the past 30 years. Magazine springs are fabricated from the highest tensile strength, heavy duty spring wire for long service life, enhanced feeding and positive slide stop operations. They have the ability to remain fully loaded for long periods of time without damage. Magazine bodies are manufactured from .027" (the thickest in the industry) aircraft grade certified 17-7 PH stainless steel, heat treated for maximum durability and service life. Dimensional tolerances are held so close that a Wilson magazine that doesn't drop free from the pistol or that your rounds are tight inside the tube as long as your pistol and ammo are close to proper specifications.