Shake Weight® will help you get your arms ripped, shoulders pumped and chest sculpted. Shake Weight uses a new workout technology called Dynamic Inertia to constantly ignite your upper body muscles while you shake it. You'll feel your muscles tightening and toning while you work out. Upper body device targets biceps, triceps and shoulders so you can get a lean sculpted chest. Weighs 5 pounds. Model # SW1000RT.