Chelsea Home Imports Computing Collections USB 3.0 4-ports Compact Hub 4 ports USB hub supports hot-swap function and no need to install driver, stably and perfectly compatible with your windows, Mac OS or Linux systems. USB3.0 transfer rate maximum to 5Gps with both power adapter and USB cable connected (Note: actual rate will depend on the capability of your device), downward compatible with USB2.0/1.1 With beautiful piano black surface and blue LED indicator, this hub can power enough to provide two hard drive. Built-in current protection system can effectively protect your device and host itself in the case of sudden electricity. Note: 2.4GHz wireless devices may not work in close proximity to USB3.0 devices or hubs; This hub is not designed to charge devices; Mac OS 10.7.4 needs to be upgraded to 10.8.2.