This mattress is made up of 2 sleeping sides, a summer side and a winter side. It has a padded winter side that will keep the heat better so that baby is warm during winter nights; and a lighter summer face which prevents perspiration during naps. It is ideal for babies with sensitive skin thanks to its anti-mite, anti-moldand antibacterial feature. , For safety and security, the zipper tab has been removed during manufacture. To open and remove the cover, a paper clip can be inserted into the zipper slider. Ensure the paper clip or any other instrument used is removed from the baby's sleep space.