Xtant z124

I Found an add for the Xtant Z124 subwoofer, and it said that it was capable of free air. However I don't fully trust the site because it said other subs were free air that I know for a fact weren't, however it was right on other cases too.....If anyone could tell me whether the Xtant Z124 speaker is actually free air or not I would greatly appreciate it.