HUAWEI Vodafone K4505 3G USB Dongle (unlocked)

What's more the modem could upgraded to support 28.8Mbps download speed.

Highlights of the Vodafone Slider USB Stick K4505 HSPA+ 3G Modem
Support HSPA+ standard
High Speed Download up to 21.6Mbit/s (prepared to 28.8Mbit/s)
High Speed Upload 5.76 Mbits/sec
Frequency: HSPA+/UMTS 850/1900/2100Mhz, GSM/GPRS/EDGE 850/900/1800/1900Mhz
Interface Type: USB 2.0
Supports all popular operating systems
No cap longer exists, but the USB connector can be extended via a USB cable.
32GB memory support (microSD card)
Qualcomm 8200 chipset
Supports four GSM frequencies (850, 900, 1800 and 1900 MHz)
Recommended Configuration: CPU 1GHx Pentium and above, Hard Disk 20MB free space
Size: 7.7 x 2.8 x 1.2 cm
Weight: 30 grams

Supported Operating System by Huawei K4505:
Windows 7 32-bit and 64-bit editions (Home Basic, Home Premium, Professional, Enterprise and Ultimate)
Windows Vista 32 - and 64-bit editions (Home Basic, Home Premium, Business, Enterprise, and Ultimate)
Windows XP (Home, Professional and Tablet Editions) Service Pack 3 is recommended
Apple Mac OS X 10.4.11 and higher and 10.5.6 or higher recommended