Collapse models aim at describing, whithin one single dynamical equation,
both the quantum properties of microscopic systems and the classical
properties of macroscopic objects.  

We discuss the properties of a stochastic differential equation describing
the evolution of a free particle subject to space-localizations.
In particular, we will see that: 

a) At the microscopic level the stochastic terms affect in a negligible
way the quantum properties of the system: accordingly, the model recovers
all know predictions of Quantum Mechanics. 

b) At the macroscopic level, the wavefunction of the center of mass of a
macro-object is very well localized in space and it moves obeying the
classical laws of motion.