A breathing mask to be placed on a user's head includes a pressure gas container in the form of one or more closed communicating tubes which form a closed or a open ring adapted to encircle the user's face in front of the user's ears, a sealing member preferably being connected in serial arrangement...http://www.google.co.uk/patents/US5687713?utm_source=gb-gplus-sharePatent US5687713 - Breathing mask
