As seen on TV. You"ll know in 60 seconds it works. - Christopher Thomas, Trainer to the pros. Free training DVD. Only 6 minutes a day. Get real, get ripped, get rapid results. With new dynamic inertia technology. Consumes muscle energy 7 times faster than traditional dumbbells. Easy to Use: High intensity rapid fire muscle reaction; Workout your entire upper body in just 6 minutes a day. Includes DVD: Step by step training routine; Simple but effective exercises; Works all fitness levels. Unique Design: Uses revolutionary dynamic inertia scientific study shows dramatic increase in EMG measured muscle activity. LifeModeler technology used by NASA and leading universities calculate that it would take 42 minutes of traditional curls to consume the same amount of muscle energy as 6 minutes with the shake weight. 7 x"s faster (Comparing total body muscle energy consumed by Shake Weight versus a traditional curl with a dumbbell of equal weight using LifeModeler human model). In order to consume the same amount of muscle energy you would have to work 7 times longer doing curls with regular dumbbells. - Shawn McGuan, CEO: LifeModeler. Product Dimensions: 14.2 x 4.4 x 4.4 inches. Made in Taiwan.