SNH48 is a chinses active idol group. SNH48 had a total of 220 original members during all their 7 generations. As of September, 2016, SNH48 has 114 members.
Like in AKB48, regular auditions to recruit new members are held, and the future successful candidates, the Research StudentsMembers (or Kenkyuusei), take part of a in-training team of members that work as sub and under for the official members in various activities (mostly the Theater Performances). And then, when any of the official members graduate, a girl is promoted to fill the space.