A sterile, metal wire or flexible rod, typically with a plastic knob at the proximal end, intended to be inserted into the lumen of a urological catheter or cannula (not included) to increase stiffness sufficiently to facilitate manipulation/introduction into the urethra or ureter (via the urethra); it is not intended to assist introduction of a percutaneous catheter. It is available in various lengths, diameters, and degrees of rigidity. This is a single-use device.