Air Mask 2 : A self-contained breathing apparatus, usually consisting of a breathing apparatus and a tank of compressed air. See: SCBA, Self-Contained Breathing Apparatus
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}