Respiratory apparatus; humidification apparatus for medical use; apparatus for the treatment of obstructive sleep apnea; breathing masks for use in treating obstructive sleep apnea; facial masks, oral masks, nasal masks, nasal cannula, mouthpieces, headgear, breathing tubes, nasal tubes, tubing connectors for medical use, tubing for medical use, nasal prongs, all being for medical purposes; parts and fittings for all the aforementioned goods