The infant side of the mattress is extra firm, designed for the flat, firm surface babies need for safety. (lullabyearth.com)
Many crib mattresses have a softer side for toddlers, so make sure to use the firm side of the mattress made specifically for infants. (safesleepky.com)
The two different sides of the mattress, and its durability, mean that you won't have to replace the mattress for years to come. (bestcribmattressreviews.com)