The QiYi/MFG 3x3 Core is the same core that comes with the QiYi/MFG 3x3 cubes, like the QiYi Sail 3x3, Thunderclap V1 and V2, and the Valk 3. It is compatible with the .

This core is a brand new core that is non-threaded. It is threaded by the screw when the screw is inserted.