ProMag Steel Rifle Magazine AR-15 9mm Colt/SMG Type 25-Round Black 25RD. The springs are precision wound using heat-treated chrome silicon wire. Bases and followers are injection molded from polymers selected for their durability. The result is quality consistency durability and reliability. Specifications for ProMag Steel AR-15 9mm Colt/SMG Type 25-Round Rifle Magazine: Manufacturer: ProMag Magazine Capacity: 25 Round Caliber: 9mm Luger Gun Model: AR-15 Features of ProMag Steel AR-15 9mm Colt/SMG Type 25-Round Rifle Magazine Magazine body constructed of heat treated steel with black oxide finish Injection molded magazine follower Magazine spring formed from heat treated chrome silicone wire Package Contents: ProMag Steel AR-15 9mm Colt/SMG Type 25-Round Rifle Magazine What firearm models does the manufacturer say ProMag Steel AR-15 9mm Colt/SMG Type 25-Round Rifle Magazine is compatible with? The manufacturer says that ProMag Steel AR-15 9mm Colt/SMG Type 25-Round Rifle Magazine is compatible with AR-15ProMag COL-A14-25RD: Steel Rifle Magazine AR-15 9mm Colt/SMG Type 25-Round Black