AnO-Ring also known as apacking, oratoric joint is a type of agasketorsealin the form of faring with a circular cross section used to preventleakage off luids. ,EPR,PTFE,PUorNitrileRubber(also knownasBUNA-N). ThisO-RingiscompatibletobeusedinGE'sLunarAnesthesiaDeliverySystems.