97% Bamboo Rayon | 3% Spandex. Made from All Natural, Organic, Hypoallergenic, and Eco-Friendly Bamboo Rayon. These Baby Hats are Silky and Smooth While Providing the Right Fit for Your Baby’s Head. Choose from a Rainbow of Modern Colors Including Solids and Prints. Available in 2 Sizes - Preemie / Newborn and 0 - 6 Months. Machine Washable.