The strings that came with it seem to tune to:
-2 unison As on the first course (5th fret 1st string of a guitar)
-3 Es,the two outside strings are the same as a guitar 1st and the middle is an octave lower.
-3 Cs, the twooutside are like the 1st fret, second guitar string and the middle is an octave lower.
-2 Gs, one like the third guitar string, the other an octave higher.

That's how I have them tuned.