The USB-C to USB Adapter lets you connect iOS devices and many of your standard USB accessories to a MacBook with USB-C port or MacBook Pro with Thunderbolt 3 (USB-C) ports. Plug the USB-C end of the adapter into the USB-C port on your MacBook or any Thunderbolt 3 (USB-C) port on your MacBook Pro and then connect your flash drive camera or other standard USB device. You can also connect a Lightning to USB cable to sync and charge your iPhone iPad or iPod.