The Hammer Black Widow bowling balls keep rolling out and dominating the lanes. The Hammer Black Widow Black Gold takes the Aggression Hybrid coverstock, and pairs it with their most angular core, the Gas Mask, to create a ball that goes long and then offers a strong backend motion when facing medium to heavy oil. This bowling ball is Carbon Fiber Infused! Carbon fiber is one of the toughest materials on earth. Hammer decided to add this material to the inner core of this ball for added strength and durability allowing them to offer an incredible 3 year warranty.