An arrangement comprising: a needle defining a longitudinal needle axis having a sharp distal tip, a shank portion, and a needle feature defining at least one localized area along the shank of increased outer diameter; a needle shield defining a longitudinal central axis, a proximal through-hole opening and a distal through-hole opening, the needle shield comprising a pocket formed therein comprising an inclined surface; a split collet disposed within the pocket, the split collet having a variable inner diameter defined by an inner bore, the split collet having a distal chamfered lead-in surface; and a biasing element disposed within the pocket for biasing the split collet against the inclined surface of the pocket; the arrangement is constructed such that as the needle is drawn in toward the interior of the needle shield, the needle feature comes into contact with the distal chamfered lead-in surface of the split collet, which causes compression of the biasing element such that the split collet no longer contacts the inclined pocket surface and the inner diameter defined by the inner bore of the split collet is expanded, thereby allowing passage of the needle feature through the split collet with a predetermined degree of interference therewith, and further as the sharp distal tip of the needle is completely withdrawn into the needle shield housing, the needle feature passes out of the inner bore of the split collet thereby removing the aforementioned compression of the biasing element, which causes the split collet to once again be biased against the inclined surface, and further in response to the split collet being biased against the inclined surface, the inner diameter defined by the inner bore is contracted such that the inner diameter is once again smaller than the distal through-hole opening as well as the outer diameter of the needle feature, thereby preventing the sharp distal tip of the needle from exiting the needle shield housing. a needle defining a longitudinal needle axis having a sharp distal tip, a shank portion, and a needle feature defining at least one localized area along the shank of increased outer diameter; a needle shield defining a longitudinal central axis, a proximal through-hole opening and a distal through-hole opening, the needle shield comprising a pocket formed therein comprising an inclined surface; a split collet disposed within the pocket, the split collet having a variable inner diameter defined by an inner bore, the split collet having a distal chamfered lead-in surface; and a biasing element disposed within the pocket for biasing the split collet against the inclined surface of the pocket; the arrangement is constructed such that as the needle is drawn in toward the interior of the needle shield, the needle feature comes into contact with the distal chamfered lead-in surface of the split collet, which causes compression of the biasing element such that the split collet no longer contacts the inclined pocket surface and the inner diameter defined by the inner bore of the split collet is expanded, thereby allowing passage of the needle feature through the split collet with a predetermined degree of interference therewith, and further as the sharp distal tip of the needle is completely withdrawn into the needle shield housing, the needle feature passes out of the inner bore of the split collet thereby removing the aforementioned compression of the biasing element, which causes the split collet to once again be biased against the inclined surface, and further in response to the split collet being biased against the inclined surface, the inner diameter defined by the inner bore is contracted such that the inner diameter is once again smaller than the distal through-hole opening as well as the outer diameter of the needle feature, thereby preventing the sharp distal tip of the needle from exiting the needle shield housing.