The Hammer Obsession Solid is obsessed with knocking down pins! This bowling ball introduces the Envy Solid CFI coverstock which is infused with carbon fiber for toughness. This strong cover is paired with the Obsession core and offers an aggressive midlane and backend reaction on heavy oil conditions. This bowling ball utilizes DOT and is Carbon Fiber Infused! DOT allows you to drill anywhere on the ball and offers toughness to the ball. Carbon fiber is one of the toughest materials on earth. Hammer decided to add this material to the outer core of this ball for added strength and durability allowing them to offer an incredible 2 year warranty.