The MDT Poly/Metal Magazines are a new advancement of the tried and true AICS pattern magazine. The combined polymer and steel magazine make for a unique" lightweight" slick feeding magazine. The body is made from high-strength polymer and features a clear window in the sides of the body to easily view loaded rounds. The Polymetal design features steel feed lips that are mated to the polymer body to ensure smooth" reliable feeding in your rifle. The metal feedlip assembly contains the latching boss" significantly increasing the durability compared to a polymer equivalent. The metal feed lips can also be easily adjusted or tuned to improve performance with other cartridges.