Wikia

The ahn-woon is a traditional Vulcan melee weapon consisting of a strip of leather with metal balls at the ends used as a whip or noose. It is used by combatants in the kal-if-fee, the traditional mating challenge during the pon farr. (TOS: "Amok Time")

In a line of dialogue scripted for "Amok Time" but not in the episode's televised variants, the ahn-woon is described, by T'Pau, as the "oldest of Vulcan weapons."