ProMag CZ Scorpion 9mm 50 Round Drum Magazine. This high capacity drum mag features a durable" steel lined DuPont Zytel polymer body with an over molded" heat treated carbon steel reinforced feed lips for lasting performance and durability in extreme conditions. Plus" a heat treated chrome silicon wire internal spring eliminates binding" ensuring the injection molded polymer follower operates flawlessly for reliable" jam free operation.