Obi-Wan Kenobi is seen wearing a Sith torture mask
The torture mask of the Sith was a type of head covering that the Sith utilized during interrogations of prisoners, most notably Jedi Knights. The mask, which appeared quite normal and concealed the entire head with the exception of the eyes, would be placed on the prisoner. This design allowed the captive to maintain their sight and witness the events unfolding around them. Despite its seemingly mundane appearance, the torture mask was infused with dark side energy, which inhibited Jedi from accessing the Force by disrupting their ability to focus.
Asajj Ventress possessed a Sith torture mask within Castle Ventress located on Rattatak, and she employed it on Obi-Wan Kenobi after the Battle of Jabiim.