Abstract: An apparatus for the easy subcutaneous insertion of a catheter into a patient is described which includes a main body member having a lockflow chamber, a stylet mounted forwardly of the body member a chamber guard releasably mounted rearwardly of the backflow chamber and a catheter with accompanying live adaptor axially mounted on the stylet with its shaft terminating short of the stylet point. The chamber guard includes a threader member which extends forwardly in a loop to abut the live adapter of the catheter whereby downward pressure on the loop directs the threader member fowward to axially displace the catheter and extend the shaft portion of the catheter beyond the stylet point.