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.