XCI is a 10-pin USB 2.0-based connector created by Theorysonic. Introduced in January 2006 to replace its predecessor, the MetroCon, XCI is used to charging and syncing data and files TheoryPhone X to TheoryPhone X5, TheoryTablet devices prior to X6, TheoryTablet Pro devices prior to X6, Portosic Touch second generation or later, Portosic Digital sixth generation or later, Portosic Mini 4 or later, and Portosic MC 5 or later. In 2016, it was replaced by a faster 8-pin USB 3.1-based UXCI type C-style charging and syncing connector.

Community content is available under CC-BY-SA unless otherwise noted.