ProMag AR-15 Magazine 223 Remington, 5.56x45mm, 300 AAC Blackout 42-Round Polymer Black

These ProMag magazine bodies and followers are injection molded from strong, lightweight polymer. The springs are precision wound using heat-treated chrome silicon wire. The result is quality, consistency, durability and reliability. FeaturesMagazine body constructed of a proprietary DuPont Zytel based polymerInjection molded magazine followerMagazine spring formed from heat treated chrome silicon wire