I am pretty sure that it's already supported. Even if it's not supported yet, it should be easy to implement support.
As for protocol, it must be one the protocols from the following web page:
https://www.traccar.org/ports-for-tk-gt-and-other-gps-devices/
I want to double check before purchasing. Will this work? Also, what protocol does it use?
http://www.amazon.com/Vehicle-Tracker-Remote-Control-Anti-theft/dp/B0095BJZ7O/ref=sr_1_6?ie=UTF8&qid=1439573224&sr=8-6&keywords=xexun