A self containe breathing apparatus, or SCBA, sometimes referred to as a Compressed Air Breathing Apparatus (CABA) or simply Breathing Apparatus (BA) is a device worn by rescue workers, firefighters, and others to provide breathable air in a hostile environment. When not used underwater, they are sometimes called industrial breathing sets. The term "self-contained" differentiates SCBA from other apparatus connected to a remote supply by a long hose. If designed for use under water, it is called SCUBA, or self-contained underwater breathing apparatus.