**What are the two types of dual-SIM phones?** The two types of dual-SIM phones are: * Dual SIM Standby (DSDS). * Dual SIM Full Active (DSFA). > **How does a Dual SIM Dual Standby (DSDS) device work?** > A DSDS device works by *switching which SIMs is active at a time.* > > **How does a Dual SIM Full Active (DSFA) device work?** > A DSFA device works by *allowing both SIMs to be active at the same time.* **What can a device do with two separate SIMs?** A device with two separate SIMs can use two separate SIMs to *register on two separate networks.* **How many IMEI numbers does a device have?** A device has *as many IMEI numbers as it does SIM slots.* **What is the purpose of the IMEI number?** The purpose of the IMEI number is *for your wireless carrier to know which device is trying to access the network.* **Where are all IMEI numbers stored?** All IMEI numbers are stored in a database called *the Equipment Identity Register (EIR).* **What devices are assigned IMEI numbers?** Devices which are assigned IMEI numbers are *any SIM-enabled devices including phones, tablets, mobile broadband routers, smartwatches, and IoT devices.* **What is the quickest and easiest way to see the IMEI numbers of a device?** The quickest and easiest way to see the IMEI numbers of a device is to *dial \*#06#.*