These magazines are designed with a unique Double Stack to Single Feed (DSSF) transition design for reduced overall height compared to the industry standard. DETAILS: MDT AICS-pattern metal magazines are manufactured from high strength steel, nitrided, and finished inside and outside with Cerakote Elite for ultimate durability, corrosion resistance, and friction reduction. SPECIFICATIONS: 10-Round: 3.055 Outside Length, 3.90″ Rear Height (same height as MDT 10-rd .308 metal magazines), 2.50 max cartridge overall length (COAL), Polymer feedlip inserts extend ~0.5″ past the end of the metal feedlip backer, thus retaining the round longer, helping ensure the tip of the round has entered the chamber before the rear of the round is released.MDT 10-round magazines are approximately shorter in height than standard AICS 10-round magazines due to MDTs unique Double Stack to Single Feed (DSSF) transition design, allowing easier mag changes when shooting prone. 10-round magazine includes 2 internal ribs that help reduce friction between the cartridge and magazine body and provide a smooth transition from a double stack to single feed at the top of the magazine. COMPATIBILITY: 223 Rem, 5.56 NATO