Memory Stick is a removable flash memory card format, originally launched by Sony in late 1998. In addition to the original Memory Stick, this family includes the Memory Stick PRO, a revision that allows greater maximum storage capacity and faster file transfer speeds; Memory Stick Duo, a small-form-factor version of the Memory Stick (including the PRO Duo); the even smaller Memory Stick Micro (M2), and the Memory Stick PRO-HG, a high speed variant of the PRO to be used in high-definition video and still cameras.