Nice Thick Material. Your little one will be more comfortable and you will get the most out of your hat. MATERIAL: 100% Acrylic. 19 48 6 14-15 38 0-3 months. 22 55.8 7 M. SIZE: One Size. Best Fit From 22 1/2" - 23 3/4" Head Circumference (Hat Size 7 - 7 1/2).