I bought this product for my new born and it was very convenient in the beginning but It is a very dangerous product because my 11 months old daughter managed to unsnap open one of the elastic snaps and crawled underneath it and got stuck between the mattress sheet and this ultimate crib sheet. I heard her at the middle of the night crying because she couldn't breathe. The bottom of this crib sheet is made of rubber . She was all sweaty and I wrote to the factory already. Snaps are a bad idea because by the time your child is 8 months old they will know how to undo them.Please be very careful using this product.