Wilson-Rogers series 47 advanced Pistol Magazines for 1911 style Autos are the choice of experienced competitors and the U.S. Military Elite Special Forces. Stainless steel magazines are designed with maximum durability and reliability in mind. The self-lubricating followers are made from blended Fiber-Fill nylon as is the removable base pad. The standard base pads are .350_ thick. Springs are specially fabricated from a heavy duty high tensile strength spring wire to reduce spring set and provide the longest possible spring life.