Perfect for anyone looking to extend their firearms magazine capacity this drum mag from ProMag holds 50 rounds and is compatible with the Sig Sauer P320.The body is constructed of a proprietary DuPont Zytel-based polymer and has a blued steel upper magazine housing. In addition it includes an injection-molded magazine follower and a heat-treated stainless steel wire.ProMagFits Sig Sauer P320 9mm Pistols9mm Drum Magazine50 Round CapacityOrder your ProMag Sig P320 50-round drum magazine online today!Searching for 9mm? Score big savings when you shop our large selection of cheap 9mm ammo for sale.