Zandalar Signet of Mojo

Zandalar Signet of Mojo is a signet that can be used to enchant any shoulder item with a caster bonus to damage & healing.

Source
The signet is a quest reward from the quest Signets of the Zandalar, which requires Exalted with the Zandalar Tribe faction in Zul'Gurub. To complete the quest, you must turn the following items:
 * 15 Zandalar Honor Tokens

You must also be Exalted with the Zandalar Tribe.