  Using collision driven molecular dynamics a system of spherical particles
interacting through an effective two length scales potential is studied. The
potential can be tuned by means of a single parameter, $\lambda$, from a ramp
$(\lambda=0.5)$ to a square-shoulder potential $(\lambda=1.0)$ representing a
family of two length scales potential in which the shortest interaction
distance has higher potential energy than the largest interaction distance. For
all the potentials, ranging between the ramp and the square-shoulder, density
and structural anomalies were found, while the diffusion anomaly is found in
all but in the square-shoulder potential. The presence anomalies in
square-shoulder potential, not observed in previous simulations, confirm the
assumption that the two length scales potential is an ubiquitous ingredient for
a system to exhibit water-like anomalies
