Most pillows are filled with polyester. This one is filled with 1.5 lbs of virgin wool from Northwest U.S. farms, encased in undyed organic cotton from Texas, handmade in northern Idaho. Wool breathes, wicks moisture, and doesn't trap heat the way synthetic fill does. It also doesn't compress permanently over time. The Woolshire is a small family operation, and this pillow is made to order. Medium loft.