The YELLOC quality tool concept is designed to keep spills of lubricants, fluids, and chemicals out of workplaces or environmentally sensitive areas. By design YELLOC prevents contaminants getting into expensive equipment when servicing hoses and manifolds.
The YELLOC design allows the plugs to be cut to fit the appropriate depth of the opening. If the plug bottoms out just cut the smaller end to shorten. Make sure to leave enough material outside the opening for later removal.