What you have there is the receiver..... you still need the hitch. Just as the decal states, if you use a weight distributing hitch (i.e., an equalizer hitch with bars) in this receiver, you can expect to tow a 6,000 pound trailer but the tongue weight (the load on the ball without the equalizer bars installed) cannot exceed 600 pounds. Lot's of info here...
I also recommend checking the VIN decal on the drivers door to be sure that the receiver accurately reflects the true towing capacity of the vehicle (the receiver decal indicates the rating of the hitch, not of the car). There should be a line marked "GCWR" (gross combined vehicle weight rating).
HTH