  A low momentum nucleon-nucleon (NN) potential $V_{low-k}$ is derived from
meson exhange potentials by integrating out the model dependent high momentum
modes of $V_{NN}$. The smooth and approximately unique $V_{low-k}$ is used as
input for shell model calculations instead of the usual Brueckner $G$ matrix.
Such an approach eliminates the nuclear mass dependence of the input
interaction one finds in the $G$ matrix approach, allowing the same input
interaction to be used in different nuclear regions. Shell model calculations
of $^{18}$O and $^{134}$Te using the {\bf same} input $V_{low-k}$ have been
performed. For cut-off momentum $\Lambda$ in the vicinity of 2 $fm^{-1}$, our
calculated low-lying spectra for these nuclei are in good agreement with
experiments, and are weakly dependent on $\Lambda$.
