Extended Gauge Models and $e^-e^- \to W^-W^-$ at the NLC

We briefly discuss two possible manifestations of the lepton number violating reaction $e^-e^- \to W_i^-W_j^{(*)-}$, which probes the masses and mixings of heavy Majorana neutrinos, at the Next Linear Collider(NLC). Cross sections for this process are shown to be potentially quite large at center of mass energies of order 1-1.5 TeV. (Talk presented at the Santa Cruz Workshop on $e^-e^-$ Physics at the NLC, University of California, Santa Cruz, September 4-5, 1995.)