Knitted with a single strand of 100% acrylic yarn using single crochet. It stretches to fit your head. It's deep, so you can wear it with the brim folded up. Please be aware that the yarn may fuzz. Measurements (laid flat): Length: Approximately 24.5cm Head circumference (middle): Approximately 27cm Brim circumference: Approximately 36cm Please allow for some margin of error. This is a handmade item, so please understand before purchasing. It will be folded for shipping, so please be aware of this. Please shape it when you use it.