?SAFETY COMES FIRST-Made from high-quality cotton and superior zipper, Unnivoll baby sleep sack is certified to meet Consumer Product Safety Commission (CPSC) guidelines, eliminate all potential risks and provide a safe sleeping environment for your little one. | ?UPGRADED PROCESS-Compared with ordinary one, our 100% combed cotton sleep sack brings 30% optimization in both comfort and breathability. Pre-washing technology effectively reduces the shrinkage rate by 50%, which ensures the baby sleeping bag can be machine washed and dried at low temperatures without distorting. We care not only for babies, but also for busy parents! | ?EASY DIAPERING-2 way zipper runs from the top to the bottom, making the lightweight sleep sack much convenient to change diapers without any interruption, especially during midnight. Equipped with zippe guard prevent rubbing on your baby's sensitive skin and protects baby's chin. Tog rating 0.5, making it perfect for nursery room temperature 75 above. | ?UNIQUE PATTERN-The 3 pack summer sleep sack printed with sky elements such as rainbow, star and planet, which can promote baby's brain and visual development. Multiple studies have shown that green, blue, and pink can relax and help babies fall asleep faster. We always design on the perspective of yours! | ? ACCOMPANY BABY'S GROWTH-Four size options available for your choice, fits baby 0-6 months, 6-12 months, 12-18 months, 18-24 months. Unnivoll sleep sack is essential for everyday use, keep your baby cozy and sleeping peacefully!