The MA5B Individual Combat Weapon System, formally known as the Individual Combat Weapon System, Caliber 7.62 mm, MA5B, was an assault rifle used by the UNSC Marine Corps and Navy throughout most of the Human-Covenant War. It was easily one of the most recognizable and pervasive infantry weapons fielded by the UNSC during humanity's conflict with the Covenant. The MA5B perfected and refined the defining features of the MA5 series rifles introduced by the ubiquitous original MA5, such as the electronic ammunition counter and enhanced electronics suite, while also introducing new features like internal attachments and a larger, redesigned magazine. The massive success of the MA5B would lead to an even more successful weapon which debuted at the very end of the war: the MA5C.