Breathing Apparatus AGA's manufacture of breathing apparatus for medical use led to oxygen gas systems for high altitudes and as safety systems in submarines. . Diving Equipment By sheer coincidence practical, light-weight diving equipment was produced during the second world war. AGA designer Dag Johannisson carried out test dives using a bottle of compressed air and a fireman’s mask attached to a valve system. Further development work resulted in the AGA Divator, which was originally intended for short-term use in firefighting. During tests in 1949 a request was made to use the Divator under water. This was achieved when a new breathing valve had been designed. The Divator was successfully developed in a number of new models, including use in military aircraft. Today this equipment is manufactured by AB Interspiro.