The Back on Track® Human Knitted Cap, Kim has a distinct modern design. It is made from a wool/acrylic blend, lined with the revolutionary polyester/cotton Welltex™ functional therapuetic fabric. The shape and soft inner forms an ideal fit, making the cap a comfortable help with relief from tension headaches, or for cold, sensitive ears. https://botcanada.com/ Sizing charts can be found https://botcanada.com/sizing-charts/