Bamboo is great for all seasons and weather. This super soft hat will keep your little ones cool in the summer and warm in the winter-"think" nature's heating and cooling system. As an eco-friendly and sustainable fabric, bamboo also contains a natural UV protection function. Fabric: 97% rayon from bamboo 3% spandex. - Silky soft, breathable, anti-static and UV protection. - Double-lined to protect baby’s head and provide warmth. - Knot at top to adjust the hat height. - Mix and match with Silkberry baby’s kimono gown, printed footies and receiving blanket.