engagement or breathing apparatus connector 13 functioning as a collar slides over the attached connector head 11 and connector body 12 to apply a positive pressure on their juncture to assure that they are not separated this design ensures security against accidental disconnections while providing minimum discomfort to the patient when the breathing apparatus connector 13 is removed and the connector body 12 is detached from the connector head 11 as depicted in fig2 and 3 connector head 11 and connector body 12 are cylindrical and when they are connected a part of each is concentrically inter aligned connector body 12 has a cylindrical coupling surface or mating surface 14 and an exposed cylindrical base 16 base 16 has a larger diameter than coupling surface 14 and the juncture of the two forms seating surface 15 seating surface 15 circumscribes both exposed base 16 and coupling surface 14 the shapes of the connector body 12 and connector head 11 may be reversed e g the cylindrical coupling surface 14 and seating surface 15 could be part of connector head 11 and connector head 11 could adopt the shape and function of the remainder of connector body 12 except that it would still be attached to the outer cannula 21 whereas connector body 12 could adopt the shape and function of connector head 11 except that it would still be connected to the inner cannula 20 as shown in fig1 4 connector body 12 contains one or more ribs 17o however if the.