i was fighting with her to get into tight sleep sacks, fighting with blankets to try and keep her warm, finally i found these. there is one for warmer weather and one for cooler. and there is so much room that babies can wear them from 0-2 yrs. there are extra snaps for when the baby is younger, and it is just very well made. it is the only non polyester sleep sack i have found, which i like bc my baby wakes up sweaty in polyester. they don't make many things this well anymore, you will see when you order it right away that it is very well made. (i.e won't fall apart and will last through many kids)