Breathable Air is a technical block used to fill airtight rooms so it can support life without using Oxygen Gears and avoid death by suffocation in the airless dimensions. They are generated by Oxygen Sealers.
In normal conditions, these blocks are totally invisible unless due to a failure of the Oxygen Sealers or interference of other mod or rendering tool.
They are unobtainable on survival or creative mode, unless by command
/give @p 3350. You can manually place them but they will disappear on the next block update that takes place nearby. Internally there are called