Upgraded Mk2 design features an improved follower, reinforced spring, and improved fitment to reduce shake High-tension steel spring for enhanced reliability and improved feeding Works great with high rate of fire AEG's Unique hexagon pattern for greatly improved grip High-strength fiber-reinforced nylon polymer shell, constructed to the same specifications as real AR magazines; incredibly strong and light weight Can be easily customized to suit each user's needs Hexmag HexID color identification system allows the user to color code magazines for specific purposes / loads or to differentiate mags from teammates Hexmag Airsoft magazines are constructed to the standard of real AR mags. These heavy duty polymer magazines are incredibly rugged while remaining light weight and easy to carry. The unique hexagonal surface pattern gives the magazines greatly improved grip while at the same time giving it a sleek look. The hexagonal patterns can be filled in with paint to customize the magazine to your preference or to differentiate your magazines from a teammates; additionally the hexagons can be filled in with grip tape to make them no slip in any situation.