Connecting to a Mobile Network
If multiple SIM cards are installed on the device, during the setup, you will be asked to chose the primary SIM for:
Phone Calls
Data
Messages
All of these options can be changed in the Settings menu from the SIM Cards option
You can also choose colors to best organize your day to day use of either SIM card.
Also, you can select your default service provider, or whether the device will always ask which SIM card you prefer to use!