Oxymask
From Tardis Wiki, the free Doctor Who reference
Oxymasks were breathing apparatus used by the Humans on Solos. They helped the Humans breath in the planet's atmosphere. Skybase workers were required to have Oxymasks with them at all times.
Ky attacked an overlord and stole his mask. He then gave this to Jo Grant in order to stop her from suffocating. (DW: The Mutants)
