Hello,
Thank your for your question,
Most of the information on devices can be found in our wiki:
https://wiki.teltonika.lt/view/FMB640
https://wiki.teltonika.lt/view/FMB630
These both devices have the same hardware features. Main differences is that FMB630 has profiles ( https://wiki.teltonika.lt/view/FMB630_Profiles ). FMB630 is compatible with camera (MCV - 300).FMB640 has the feature to be updated using Fota Web platform. FMB640 supports "Continental" tire sensors.
Most of our devices support "Voice call" using bluetooth hands free set up, device does not have audio/voice connectors for wired connection.
Hope this helps,
If you have further questions please feel free to ask.
Regards, Teltonika support.