The D-Link DUB-H4 20 is a Hi-Speed Universal Serial Bus 20 4-port hub with backward compatibility to USB (Universal Serial Bus) 10 & 11 It provides an out of the box industry standard that allows connection of up to four USB (Universal Serial Bus) peripherals or devices to your USB (Universal Serial Bus) ready PC or Mac The D-Link DUB-H4 is targeted at PC & Mac users that are expanding the number of USB (Universal Serial Bus) ports on their system The D-Link DUB-H4 20 is designed to provide quick & easy access to the four type "A" downstream ports for connecting USB (Universal Serial Bus) peripherals devices or other USB (Universal Serial Bus) hubs A single type "B" upstream port connects the DUB-H4 to the host computer or another USB (Universal Serial Bus) hub enabling up to 127 devices to be connected by cascading multiple hubs Configured directly by the operating system the D-Link DUB-H4 20 operates seamlessly with both Microsoft Windows & Apple Macintosh Operating Systems As a standard USB (Universal Serial Bus) hub the D-Link DUB-H4 buffers USB (Universal Serial Bus) data from any attached peripheral in compliance with USB (Universal Serial Bus) specifications to provide an invisible extension of the USB (Universal Serial Bus) bus Supporting both low speed (15 Mbps & 12 Mbps) & Hi-speed (480 Mbps) devices each port creates a bridge between the peripheral & host computer Diagnostic LED&s located on the top of the device provide power state (self-power) & port status on each port The DUB-H4 20 is packaged with all necessary documentation a 6-foot hi-speed USB (Universal Serial Bus) 20 &A& to &B& cable & an AC power supply to ensure that the user is able to easily & quickly install & use the device