A breath mask or respirator was an apparatus that was strapped to the face. It usually had a hose to a filter or air canister, which supplied the wearer with fresh, breathable air.
Breath masks also safeguarded the wearer from minor differences in atmospheric pressure. Typical air canisters provided one hour of breathable atmosphere before replacement of the canister was required. The typical breath mask weighed roughly 1.5 kilograms. These masks offered no protection from extreme temperatures or a hard vacuum.
The content of the canisters—also known as air-tanks or breather packs—varied depending on what species was wearing it. As a member of the breather Gand subspecies, Zuckuss wore a respirator, since he needed to breathe ammonia, as oxygen atmospheres were poisonous to him. He kept the ammonia-filled canisters to his breath mask on his person. The tubes of his respirator were connected to a gas-processing unit, which he carried on his back.
In some cases, respirators were built into a person as cybernetics, if they suffered severe enough injuries that they cannot live otherwise. Notable examples include Darth Plagueis as well as Darth Vader and General Grievous.
All Kel Dor who left Dorin wore antiox breath masks because they needed helium and their own native gas, as oxygen was poisonous to them as well. The Ubese also wore breath masks. Breath canisters typically weighed about 1 kilogram and cost 25 credits. The breath masks also varied in cost, but from 32 BBY to 8 ABY, most models were available for 200 credits.