  A concentric charged thin-shell encircling a Reissner-Nordstr\"{o}m black
hole screens the clectric / magnetic charge completely to match with an
external Schwarzschild black hole. The negative mass thin-shell is shown to be
stable against radial perturbations. It is shown further that by reversing the
roles of inside Reissner-Nordstr\"{o}m and outside Schwarzschild geometries the
mass of the appropriate shell becomes positive.
