The JW Hol-ee Roller X is a unique, thick rubber ball for dogs. It's tougher and thicker than the traditional Hol-ee Roller. This product is designed for tough dogs and tough chewers. Hol-ee Roller X has strategic cut outs covering the ball so the dog can grab it and pick it up. It's also great for games of tug-of-war. The cut-outs can also be easily filled with treats or small toys for long-lasting boredom-busting fun.