NOTE: PHONE APP NO LONGER SUPPORTED. JAXJOX Adjustable Weight Dumbbell is perfect for targeting the legs, chest, back, arms, shoulders, and core. Its sleek design feels like a standard dumbbell whether you are lifting 8 or 50 pounds. Both ergonomic and versatile. The Dumbbell replaces an entire rack of weights and packs 100 pounds into two adjustable dumbbells. Its space-saving design allows you to store it anywhere in your home and makes it easy for you to transport it.