Black holes with zero mass

We consider the spacetimes corresponding to static global monopoles with in terior boundaries corresponding to a black hole horizon and analyse the beh aviour of the appropriate ADM mass as a function of the horizon radius r(H) . We find that for small enough rH, this mass is negative as in the case of the regular global monopoles, but that for large enough rH the mass become s positive, encountering an intermediate value for which we have a black ho le with zero ADM mass.