The S-300P is a mobile system, that can be used in all weather conditions and that is able to engage enemy aircraft, at all altitudes, as well as flying objects with low Radar Cross Section, incoming at low altitudes (like cruise missiles). The upgraded S-300PS is also able to engage ballistic missiles, and it is the only variant known to have been equipped with nuclear warheads. The Western counterpart to the S-300P is the MIM-104 Patriot.