An SCBA is a respiratory protective device that supplies breathable air from a source carried by the user, completely independent of the surrounding atmosphere. These units are widely used by firefighters, emergency responders, and industrial workers who face exposure to hazardous airborne substances. https://www.vevioz.com/post/1883415_self-contained-breathing-apparatus-scba-dipti-fire-services-https-diptifire-com.html