text: However , because the USB 2.0 specification , which introduced high-speed , incorporates and supersedes the USB 1.1 specification , any compliant full-speed or low-speed device is still a USB 2.0 device . Thus , not all USB 2.0 hubs operate at high-speed .
simplified: The hubs themselves are also USB 1.1 or USB 2.0 compliant .