Aden and Anais Princess Posie Sleepbag is made of 100% muslin cotton which keeps baby warm but not overheated.  Aden and Anais sleepbags are meant to be worn over pajamas to keep baby warm without the danger of loose blankets.  This design is all girl with beautiful shades of pink that distinguishes pretty baby girls.  Aden and Anais Princess Posie muslin cotton sleepbags have an easy to access zipper that opens from the bottom for easy diaper changing any time.  Aden and Anais sleepbags are machine washable.  Size Small is for up to 6 months, 23"-28" and 10-18 pounds and Size Medium is for 6-12 months, 26-31" and 15-24 pounds.