Zoom Telephonics #4598 7.2 Mbps 3G+ Unlocked Tri-Band USB Modem for AT&T & Other GSM Services

The Zoom Telephonics 7.2 Mbps 3G+ Unlocked Tri-Band USB Modem works with AT&T in the US and most service providers around the world. It supports data rates of up to 7.2 Mbps on downloads and 5.76 Mbps for uploads using a wide range of cellular data communications standards including HSDPA, HSUPA, UMTS, EDGE.

The modem is activated by plugging in the SIM card from a service provider. Unlike other modems, the modem is not locked to a specific service provider and can use a data SIM from many GSM service providers or a voice/data service SIM from a smartphone. A change to the service provider is accomplished by simply sliding out one provider's SIM and replacing it with another provider's SIM.

GSM frequencies can vary from country to country. It uses any of three high-speed frequencies, which provides broad compatibility with high-speed GSM-based mobile data services in countries around the world.

It supports voice calls using a PC with a microphone and speakers or headphones. This allows the use of the SIM from a smartphone to be used by the modem while retaining voice communications.

A micro-SD slot on the modem accepts a memory card for up to 8 GB (Gigabytes) of memory. A simple slide-in of a micro-SD memory card allows the modem to double as a portable storage device to maximize the flexibility of available USB ports.