GOOQ High Technology Slim Power Charger Conversion Converter Cable Adapter for Lenovo Thinkpad X1 Carbon 0B47046 Ultrabook Notebook PC (Lenovo Converter Usb Cable with 5.52.1 Converter) Work with Lenovo Thinkpad X1 Carbon 0B47046 Laptop Connector: one side is 7.9x5.5mm female plug, another side is Square male plug for X1 Carbon Ultrabook. Includes a usb port which could charge other smartphones or tablets, when charging your lenovo laptop Easy to carry around on travel Please make sure the Tip Connecter size of the AC adapter are identical to what your need before buying.