SHIPPING INCLUDED Strength training with a twist. SupraBar Cable Curl Bar w/revolving handles. The all-purpose weight bar and cable system that runs rings around the others. The SupraBar and the SupraBar Cable System utilize the biomechanical process of supination - the inward and outward rotation of the wrist - to improve strength training benefits. By utilizing movable and rotating grips, all of the SupraBar products isolate exertion to the targeted muscle group while relieving stress on tendons and joints.