No matter how many crunches you do you just can't get that ab definition you've always dreamed of? This is the perfect solution. It makes working out your abs easier and more effective. The dual roller is an extreme yet effortless workout. The Anti-slip kneeling board protects your knees and is extremly helpful. The resistance can be adjusted accordingly basd on your current fitness level. More than 40 different exercises can be done with it. Overall it's an exercise system for the whole body.