  We discuss the most relevant features of a BSM model with extra gauge
symmetry, the so called 331 model. The gauge group is $SU(3)_c\times SU(3)_L
\times U(1)_X$ impling the presence of extra gauge bosons, both charged and
neutral, as well as extra/exotic fermions and an enlarged scalar sector. We
present the relevant phenomenology of doubly-charged gauge bosons, which are a
distinctive feature of a version of the 331 model, and discuss the role of BSM
phenomenology as a tool for testing GUT (inspired) theories.
