Include: 3 pieces DVD, Manual, BlowerSize of ball: 8 inchesAfter test, the effect of sport can up toquadruple!Get beautiful and sculpted abs fast with the Bender Ball. It gives you workout that is up to 408% more effective than ordinary crunches. This means you can spend less less time working out to sculpt beautiful abs fast.The Bender Core Method utilizes the Bender Ball and Leslee Benders innovative and original Selective Stabilization system. This method of training us designed to target your abdomen muscles from all sides and from top to bottom, defining even those hard to reach lower abs.The Bender Ball is yet another piece of As Seen On Tv exercise equipment and it makes me wonder if I can stand another one. But, Leslie Bender uses the Bender Ball to target core abdominal muscles and this simple little accessory really does the trick.To me it appears the Bender Ball forces the user to develop those muscles which provide the support needed to do the harder ab workouts. The results are better posture and a feeling of being grounded when you're walking around. I believe it's because your body moves about slightly while your using the bender ball and you have to compensate a bit to get through your routine. This really works those muscles neglected by those machines which have the perfect fit and cradle your body.