EXTRA STRONG: Ideal for any size and shape. You can put your entire body weight onto the Stronger Spiky Massage Ball.Pain Relief Product: This aqua pressure ball includes strong grip and tones your muscle and improves your blood circulation. Overall, it reduces the stress and enhances your workability.TRAIN HARDER FOR LONGER - The spiky layer offers a stimulating effect and increases circulation throughout your entire body both pre and post workout. This will hit all trigger points and rejuvenate all areas of your body, so you can train harder for longer.Improves Health Perspectives: This ball is also improves your health by doing daily exercise. It will tones your body muscle and repairs your internal organs.