I have a Macbook Air of first generation, which unfortunately has only one USB port. If I want to run the notebook even on the LAN or need, I need the Apple USB Ethernet Adapter, because there is no real Ethernet interface. So me is no USB port more for a mouse or the like is available. With this adpater I can expand your notebook easily and without any software installation by three additional USB ports. The network connection with the Apple USB Ethernet Adapter in conjunction with a mouse to work properly on the Amazon USB Hub. Buy recommendation !!!