Talented girl group SISTAR recently made their way to the Navy's 2nd Fleet Headquarters located in Gyeonggi-do, where they put on a special show for those serving their country as part of an open concert, hosted by SBS. On September 6th, SISTAR performed "So Cool" in addition to SISTAR19's "Ma Boy", but with all four members instead of just two. Check out the fanboys screaming their heads off performances below! == < SO COOL > - < Ma Boy > - Source: Joongang via Naver