Plagueheart Bindings

Plagueheart Bindings are wrist armor for warlocks. They are part of the Plagueheart Raiment armor set.

Source
The bindings are a quest reward from Plagueheart Bindings (quest), crafted by a vendor from Desecrated Bindings, an item which drops from Grand Widow Faerlina and Anub'Rekhan who currently reside in Naxxramas.