The iD4 MKII can be connected to either a USB-C port using the included cable or to a USB-A 3.0 port using a a USB-C to USB-A cable (not included).
The small rounded USB-C is the newest connector type for USB and is now being found on more and more computers. The iD4 MKII will work perfectly on a USB-C port and the extra power provided by a USB-C port even allows for a little more volume from the headphone amplifier!
BEST PERFORMANCE IS DELIVERED BY USE OF A USB3 PORT
The rectangular, slightly later USB-A port is the classic USB connector type that has been used for many years. The iD4 MKII will also work on a USB-A port just fine and will provide full phantom power to a mic.
Important note - The USB-A connector must be able to provide 900ma of current (as specified in the USB3.0 specs). A vast majority of USB-A ports on computers from the last 6-7 years will be able to provide this.
If you're unsure whether your USB ports will support this then please contact your PC manufacturer for more information.
If you do not have ports which meet these requirements then we would reccomend the use of a Powered USB hub with the correct ports.