Wilson Combat's 1911 magazines have proven inherent reliability, durability and the ability to remain fully loaded for long periods of time without damage. The magazine springs are specially fabricated from the highest tensile strength heavy duty spring for long service life, enhanced feeding and positive slide stop operation. It is manufactured from aircraft grade certified stainless steel, and heat treated for maximum durability and service life. his 10-round magazine is compatible with a 45ACP 1911, has a wrap around base bad, and a stainles steel finish.