Lancer Systems Magazine, L5 Advanced Warfighter, 300 Blackout, 20 Rounds, Fits AR Rifles, Polymer, Opaque Black 999-000-4280-05 Lancer set out to engineer a better magazine; one with the reliability of steel" durability of polymer" and weight of aluminum - the L5AWM. The magazine design includes a one-piece" wrap-around steel feed lip assembly and an aggressive surface texture to create the ultimate hybrid magazine tough enough for military" LE and commercial use. The internal geometry of the Advanced Warfighter Magazine is a constant curvature utilizing a non-tilting follower for reliable feeding. The body and component materials are corrosion and chemical resistant" passing military chemical testing.