Well it gives voltage, current, resistance, inductance and moment of inertia... What more are you wanting!
(Google finds a better datasheet at JameCo btw)
Actually the part number is 39BYG101-1, the -1 probably relates to the non-standard connector, the datasheet
implies 4-wire bipolar. Its not clear whether the 5th connection is because this one is unipolar 5-wire motor
or its simply a case-ground wire... Multimeter could help determine this.