Gently used. A lot of life left! Silky-soft hypoallergenic merino wool lining and the finest organic cotton outer. Unlike other brand sleep sacks that come in either winter or summer weight/TOG rating, the Woolino 4 Season Sleep Bag can be used year-round. It’s suitable for room temperature 63-75F (17-24C). Because of merino’s unique ability to regulate body temperature, it helps keep your baby warm when it's cold and cool when its hot. It has a universal size so it can be used for babies 2 months up to 2 years old. For smaller babies, simply close the underarm snaps to adjust the fit. You don’t have to buy a different sleep bag every few months. Woolino Ultimate 4-Season Sleep Bag is the only baby sleep bag your baby needs, in winter or summer, until they turn two years old. It features double shoulder snaps and a two-way side zipper, so it opens up completely flat for easy dressing without waking the baby. For easy nighttime diaper changes, you can open the bottom only. Zipper-pull guards protect baby's skin and discourage baby from chewing on the zipper pull. A safer alternative to loose blankets Helps your baby stay covered through the night, replaces loose blankets in the crib, and promotes back sleeping.