In {HEAD ~ an obturator} comprising {TAIL ~ a forwardly tapered male plug} with a shaft extending from the forward end thereof, said plug including locking means for releasable engagement with projecting dogs on a catheter fitting having an inwardly tapered smooth female portion upon insertion of the obturator into the catheter fitting, the improvement comprising: 
In { HEAD ~ an obturator } comprising { TAIL ~ a forwardly tapered male plug } with a shaft extending from the forward end thereof , said plug including locking means for releasable engagement with projecting dogs on a catheter fitting having an inwardly tapered smooth female portion upon insertion of the obturator into the catheter fitting , the improvement comprising :
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH