They are of Grisha-make and are worth consideredably more to one of us than anything else we may possess. They are lined with fibers made of metal and other materials that will block blows and even weapons, including bullets. Typically they come in the color of your Order of Grisha, but since you're not one, I would have to be persuaded and given materials to make you one. Grish also have one for summer which is lined with cooling fabric and the one for winter is lined with pelts and wool for the bitter winters we had in Ravka.