What developmental toys do you recommend for preemies?

I have a preemie baby, I don't give my son a particular toys for a preemie baby. What I'm giving my son is a educational toys pro syempre dapat alam natin kung nauukma ba sa buwan ni baby yung kayang nyang gawin. hope this link will help http://www.babycenter.com/0_developmental-milestones-understanding-words-behavior-and-co_6575.bc.