  We explore an extension to the Standard Model which incorporates a vector
field in the fundamental representation of $SU(2)_L$ as the only non-standard
degree of freedom. This kind of field may appear in different scenarios such as
Compositness, Gauge-Higgs unification and extradimensional scenarios. We study
the model in which a $Z_2$ symmetry is manifest, making the neutral CP-even
component of the new vector field a vectorial dark matter candidate. We
constraint the parameter space through LEP and LHC data, as well as from
current dark matter searches. Additionally, comment on the implications of
perturbative unitarity are presented. We find that the model is highly
constrained but a small region of the parameter space can provide a viable DM
candidate. On the other hand, unitarity demands an UV completion at an scale
below 10 TeV. Finally we contrast our predictions on mono-jet, -$Z$, -Higgs
production with the ones obtained in the inert Two Higgs Doublet Model.
