the sides of the arms 32 33 the insertable end 39 of the clamp 30 is smaller in diameter than the locking rachet end 35 of the clamp 30 the locking ratchet end 35 has an opening 31 longitudinally along one of the sides that allows the diameter of the inner surface 44 to be decreased when the clamp 30 is tightened a lip 52 circumscribes the edge of the depending tube portion 39 of the clamp 30 the lip 52 secures the clamp 30 against the neck 24 of the base 20 by snapping into the receiving groove 56 on the inner surface of the neck 24 of the base 20 the seating of the clamp 30 into the neck 24 facilitates angulation of the neck 24 of the base 20 in addition this configuration allows the clamp 30 to rotate around the neck 24 of the base 20 for proper positioning and thereby promotes superior angular tilting of the cannula 16 by ensuring that the arms 32 33 of the clamp 30 are out of the line of angulation fig8 is a prospective view of the clamp 30 as described above and also illustrated in fig5 and 6 the two arms 32 33 are shown extending outward tangently from the clamp 30 beneath the point where the arms 32 33 extend outward from the cylindrical tube portion 35 of the clamp 30 the slit 37 that enables the inner diameter 44 of the clamp 30.