7-port desktop hub. Power adapter allows hub to work with or without a computer. Compact anti-slip design with 4 top-load ports for convenient device connection. On/off switch provides energy efficiency. PC and Mac compatible. USB 2.0 or 1.1. Supports hard drives, printers, MP3 players and flash drives. Plug-and-play. 4390300 includes 2.5V AC adapter. 4390200 includes 2.0V AC adapter. Includes 2.5V AC adapter