With RUIM support ( similar to sim, in GSM mobile system ), you can transfer information ( stored on the RUIM chip ) from one device to another.
The product allows users to access CDMA networks, including high-speed CDMA 2000 1X networks, and IS-95A. CDMA 1x also has a call function like a regular mobile phone, users just need to plug in a headset to be able to "Hello" without fear of running out of battery.