Built with patented Thunder Heat™ technology, this fast pitch softball can be used in any temperature because it is less susceptible to compression changes. The 11" ball features a high-density, precision-blended, cross-linked polyurethane center and has a durable yellow leather cover to make the ball resilient and give pitchers an authentic feel. Very durable and strong, the ball has a .47 COR rating and 375 lb of compression. Approved for use in Pony League division softball. Sold in a dozen.