This magazine was designed for full size 1911 models which are chambered in the extremely powerful 10mm Auto cartridge. The magazine was made from a high quality stainless steel which has been polished all over to ensure flawless feeding and function. Additionally a Black Nitride coating has been applied to the magazine which serves many purposes. Primarily as an insurance policy for the magazine to ensure it remains durable for many years, but secondly as a low glare non reflective finish should you choose to carry spare magazines on a belt line in a concealed carry situation.