Features:

Complies with OHCI 1.0, USB 1.1
Complies with EHCI
Data transfer rate support from 1.5M, 12M and 480Mbps
Supports up to 127 devices
Supports devices hot swap and wake-up
Supports all USB compliant pripherals
LED Display (system status)

Specification:

Model No. RHUB-210
Chipset NEC 101
Bus Interface USB 2.0
OS Supports
PC:Windows 98SE, 2000, ME, XP, Vista 32/64bit
Mac:Mac OS 8.6 to 9.x, Mac OS X or greater
Connectors 4 x Typa A USB ports
Accessories 1 x Manual, 1 x USB Cable, AC Power Adapter
Dimension 100x67x25 mm (not including power adapter)
Weight Unit Weight (not including adapter): 80g
Power Adapter: 560g
Warranty 1 Year

The product came in a nice little box. The 4-Port Hub goes on newegg right now for about $15. Also, as of June 2009, there is a special on newegg. If you buy Rosewill 7-port hub, you get this one free. Currently, this 4-Port Hub is connected to my 3 external enclosures with harddrives (the ones that have separate power adapters) and laser printer. I turned all of them on and they worked just fine. On the other hand, when I tried to get the Western Digital hard drives (with NO separate power adapter) to work, it did not work at all. It seems like the 4-hub adapter doesn't have enough power for the pocked hard drives.

Pros:
Free with purchase of 7-port hub at newegg
Handles external enclosures with separate power adapters

Cons:
Can't power pocket harddrives
Pricey



In my opinion it is better to add $10 and buy Rosewill 7-port hub instead of this one and not worry about pocket harddrives, although, RHUB-210 4-Port Hub adapter might be just enough to suit your needs.

Official product web site