The Troy VTX 47” SupraBar deluxe curl bar with revolving handles is designed to increase upper arm mass, strength and definition. Used with any 2” Olympic plates, this bar isolates and intensifies development of the biceps and forearms through the biomechanical process of supination – the inward and outward rotation of the wrists. This SupraBar isolates exertion to the targeted muscle group while relieving stress on tendons and joints.