Hammer, as Faball, was the leader in the bowling industry for urethane technology in the 1980's. Hammer is taking that technology and merging it with the iconic Black Widow bowling ball line. The Hammer Black Widow Urethane takes the successful Gas Mask core and wraps it with a urethane coverstock. This combination offers the hook of the Black Widow with the predictability and consistency of urethane. 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.