Championship Mercury Ultra cloth is a 19-ounce woolen-hybrid fabric that looks and plays like the much more expensive worsted cloth. Mercury Ultra is a 75% / 25% wool and nylon blend creating a very fast playing surface and is the preferred cloth by many leagues including the APA, VNEA and BCA. If your looking for the speed of worsted but don't want to pay the higher prices associated with worsted fabrics this is the cloth for you!