1. What is the main difference between the Merlin U530 and Merlin U520?

The Merlin U530 uses the UMTS network or GPRS network to transfer data wirelessly, and was designed to use the UMTS and GPRS frequency band allocated in Europe. The Merlin U520 only uses the UMTS network to transfer data wirelessly, and was designed to use the UMTS frequency band allocated for North America. Any updates will be available from your service provider.