This is an AR-15 magazine .223 / 5.56 with a no-tilt follower, called the "E4" (these are the updated Gen 5 magazines), polymer, 40 round capacity, manufactured by MSAR.
This is an AR-15 magazine .223 / 5.56 with a no-tilt follower, called the "E4" (these are the updated Gen 5 magazines), polymer, 40 round capacity, manufactured by MSAR.