This is a set of promo cards that was given out with the Vitanvox miniature, which itself is not part of the game.
The promo centers on the Banshee Dura special rule. It contains one Banshee Bedlah gear card, which confers this rule to the survivor wearing it, a Banshee Loincloth which strengthens the effect, and one Glossary card that describes the rule.
Banshee Dura X
A special rule. At the start of your act, gain (or lose) howling tokens until you have X of them. During your act or a survival opportunity, you may spend 1 howling token to do one of the following:
Gain [move], which must be spent immediately, limit once per round.
Gain [activation], which must be spent immediately, limit once per round.
Perform a survival action using the howling token in place of survival.
Gain +1 STR token until the end of the round.