12-Port USB 2.0 HUB w/ AC Adapter 1 upstream to 12 downstream USB ports. DC jack for connecting an external AC power supply (included). Supports USB switching methods. Asynchronous notification to eliminate the need for host polling to determine if a device has been added, removed, and hot-plugged. Supports up to USB 2.0 480Mb/sec transfer rates. Power adapter maximum current: 3.5a Maximum current output to ports: 500mA per port.