Official ball of Team DeMarini. Lab Compression tested to 300lbs., they're as hard as the brass on your bench. That's right, we've squeezed this ball so you don't have to. The inside of this rock is made with space-age Polyurethane! From the U.S.A! Now with bigger bounce-to-the-ounce, these .52 COR bad boys are available in both a hard-wearing genuine Leather and Leather-like skin.