Lucco 7.9x5.5mm Power Adapter Cable Converter for Lenovo Thinkpad X1 Carbon Notebook Pc Fit for Lenovo Thinkpad X1 Carbon 0B47046 Laptop. Specially designed with a 5v 1a USB port. Convenient for you to charge other usb devices. Size: female: 7.9mm*5.5mm. Male: square male plug for X1 Carbon Ultrabook. Note: Please make sure the Tip Connecter size of the AC adapter before ordering.