Our granddaughter has asthma, so I looked for something that would be the safest & most comfortable for her. This is perfect. The size noted in the description (at least when I bought it), by the way is slightly incorrect. It is a standard size mattress. The posted dimensions were a little longer than standard, so I spent a lot of time looking for organic crib sheets and mattress pad that I thought would stretch a lot. That was unnecessary, as it IS standard, which I wanted. Fits well in the crib. Not too heavy, either, for changing sheets. Love it.