空くう気き呼こ吸きゅう器き

• マスク

  マスク is a general mask for covering the mouth and nose, while 空気呼吸器 is a full self-contained breathing apparatus.

• 酸さん素そボンベ

  酸素ボンベ is an oxygen cylinder, often part of a breathing apparatus, but 空気呼吸器 refers to the complete device.

Compound of 空気 (air), 呼吸 (breathing), and 器 (device).