Abstract: A conduit plug has a securing element, a retainer, an enclosing element, an elastomer, a pusher and trapezoidal stops. The retainer has an outer threading corresponding to the inner threading of the securing element and extensions each extension having a wedged end formed on a free end of the extension. Each extension extends through a corresponding one of the holes in the enclosing element, through holes in the elastomer, bores in the pusher and slits in the stops so as to securely engage with a face of the trapezoidal stop. The mating of the inner and outer threading is able to deform the elastomer so as to accomplish the purpose of water leakage prevention.