Notice :when you connect the Large capacity hdd or other Large Power devices, you may need to buy an external power adapter to let it work, because USB port have no enough power to drive it, thank you ! The main function of the USB HUB is to transfer data, not to charge the device. Every port with independent control swith Every port has LED power light Can be driven 500Gmobile hard disk without external power supply Backflow prevention circuit design,in order to prevent electric current flow back to the device Automatic switching between self-powered and bus-powered mode Supports Plug&Play Power adapter is 5V 1A High Compatibility This hub is USB splitter 3.0 for keyboard, wireless mouse, HDD, camera, good USB 3.0 hub for PS4, for Xbox, for MacBook Pro, for Surface Pro, for iMac System Compatibility This powered USB hub compatible with most Windows 10, 8, 7, Vista, XP, Mac OS X, Linux (kernels 3.0 and later) packing list: 1*4 port usb 3.0 Hub