A surgical drainage bag has a vent opening in a rear wall of the bag. A first mount is attached to the rear wall of the bag and has an opening registering with the opening in the rear wall. A second mount has a tubular plug which is a press fit in the opening in the first mount and communicates with...http://www.google.es/patents/US4479818?utm_source=gb-gplus-sharePatente US4479818 - Surgical drainage bags
