Your safe should have came with three (3) keys, two identical with black coverings and one plain master. You need to open the door with the master to install the batteries and set the combo. After setting the combo you need one of the black keys to open while using the combo. The door will not open with just the combo, you need a key also. The master key need to be secured in a safe location ( not in the safe) Ito be used in case the batteries fail or combo is forgotten.