Sunny Health & Fitness Power Twister MATERIALS: The solid steel bar design ensures durability and support during more vigorous routines. Coiled spring resistance provides a more challenging workout to increase biceps, triceps and core with this sleek fitness tool. ERGONOMIC: The power twister is compact and lightweight (1.1 lbs) so you can bring the tool to the gym or to a park. Easily store away in a closet or under the bed when not in use. NON-SLIP GRIP HANDLES: Molded slip-resistant handles with strap are an added safety feature to keep the fitness tool stable and efficient. UPPER BODY WORKOUT: Suitable for better upper body strength. Use the grip method to engage muscles in your arms, core, and pectorals. Hold the device close for a contracted exercise or farther from your body for a more challenging workout. SOLID STEEL BAR: Its solid steel bar with coiled resistance provides you with enough stability and tension for an intense upper-body workout.