A vector-like extension of the standard model for heavier quarks and leptons with SU(2) X U(1) gauge symmetry and only one Higgs doublet is examined. This scheme incorporates infinitely many fermions and avoids the appearance of a strongly interacting sector. The model is perturbatively well controllable, and constraints such as b .... sy and GIM suppression in general are naturally satisfied if the on-set of heavier fermion mass scale is chosen at a few Te V. In this scheme, the physical Higgs

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... particle generally mediates leptonic as well as quark flavor-changing processes at a rate below the present experimental limit. Vector-like models, if suitably defined, provide a viable and interesting scheme for physics beyond 1 TeV.