The Magpul PMAG AC/AICS is a reliable and durable polymer magazines built specifically to be compatible with short action Accuracy International Chassis Systems type bottom metal and 5.56 NATO/.223 Remington cartridges. These magazines are built using the GEN M3 technology and feature the latest advancements in both material and manufacturing process. This magazine provides you with a superb value due to the fact the magazine is economical, lightweight and durable. Specifications and Features:Magpul Industries Item Number: MAG110010 Round, Bolt Action MagazineCaliber: 5.56x45 NATO / .223 RemingtonAccepts a Cartridge Overall Length of up to 2.39"Next-generation Impact and Crush Resistant Polymer ConstructionSelf-lubricating Follower for Increased ReliabilityLong Life Stainless Steel SpringPaint pen dot Matrix for Identification MarkingsFlared Base Plate for Positive Control and Ease of RetrievalWeight 2.7 ouncesHeight 5.01"Black