A.  Although it may be just a big mason jar, I'm going to assume you received a jar cigar humidor (shown). It's not a humidor in the traditional sense, but it sure keeps cigars fresh - and they will last a lifetime if properly managed.

The main drawback to a jar humidor is, it seals so tightly that humidity tends to build up quickly. You might even find yourself leaving the jar's lid unlocked much of the time to allow a little airflow. Plus, they need to be kept out of direct sun or lamp light. If you put any kind of humidifier in there, I would suggest nothing more than a DryMistat stick. I would also add a digital hygrometer so you can keep tabs on the conditions, and a small block of cedar from a factory box for a little wood humidor fragrance.

Finally, be careful when removing any un-celloed cigars from the jar. If the jar is very full, sometimes the wrappers can tear while pulling the cigars out. Therefore, I suggest you keep the cellos on any cigars you plan on storing in the jar.