Woolino 4Season Ultimate Baby Sleep Bag, Merino Wool. 2 Months - 2 Years. Star Gray. ***Fair condition. Pre-owned with signs of wash wear and small interior stains, and there's a small hole in one of the sides that we used for my son's feeding tube (see photos), but these are so well made and there's plenty of life left for your little one.*** These sleep sacks are the best!: * Can be used year-round: hypoallergenic merino wool keeps baby warm in the winter and cool in the summer * Universal sizing: fits babies 2 months to 2 years This means this is the only sleep sack you'll need, and you don't need to buy tons of different sleep sacks as your baby grows and for different seasons.