Graco's Ultra Premium 2-in-1 mattress is a great mattress for babies or toddlers. It fits perfectly in both our baby's crib, and our toddler's toddler bed. I love that it has two sides, both a softer side for toddler's, and a firmer side for baby. Perhaps the best part of this mattress, is the zip-able removable cover that is water resistant and machine washable! It is advertised as being made of a high quality breathable foam for safety and comfort, and i have to tell you this mattress is much better than our previous one. My almost 3 year old son sleeps much better on this mattress, as he can move without all the "plasticy" sounds of our cheaper mattress.  Overall, a great investment for baby that will last all throughout the toddler years as well!