By "locker" he probably means a limited slip diff.
The problem being that people that do not know these things call them different names.
If you are worried that it is a spool type (no slip at all) then I think you will find it isn't. Spools do not allow the wheels to rotate at different speeds on corners at all. That looks like some type of limited slip to me.
Use oil or an oil additive designed for a limited slip diff. If you find the car will not drive in a circle you will know I was wrong.