We always recommend you check your crib or cot’s mattress doesn't sag and lies flat with no tears or holes. It’s also important to keep it clean and dry for your baby’s comfort, with frequent mattress changes for each baby to ensure overall safety. If your Nex2Me Forever bedside cot needs a new mattress, it’s advised to use the Chicco original and official replacement. This mattress is only compatible with the Chicco Next2Me Forever cot and perfectly fits the Chicco Next2Me Forever Cot sheets and mattress protectors (sold separately). It allows air to pass through to reduce sweating, so your baby enjoys a comfortably cool night’s sleep. The mattress cover is made of resistant fabric and is completely removable and washable. The padding can also be hand washed in cold water for easy cleaning. It’s a good night’s sleep guaranteed.