This is a 4-port hub compliant with USB 2.0 specification. It is able to support 12 M transmission distance, and comply with USB-IF Battery charging specification 1.1. This Hub has USB charging detection mechanism, each port supports Battery charger function, but only one can be the Battery charger port at the same time. On the other hand, users can only choose one of four ports as the port with battery charging function at the same time. It is the USB Hub for you easily connecting up to 4 USB 2.0 devices to your computer, such as an MP3 player, digital camera, or printers. Its streamlined, sleek and compact design is the perfect solution for USB port expansion.