  We discuss the generalisation of the Snyder model that includes all possible
deformations of the Heisenberg algebra compatible with Lorentz invariance and
investigate its properties. We calculate peturbatively the law of addition of
momenta and the star product in the general case. We also undertake the
construction of a scalar field theory on these noncommutative spaces showing
that the free theory is equivalent to the commutative one, like in other models
of noncommutative QFT.
