36-inch hex winding bars, 5/8 to 1/2 inch, part number 588. They are the longest hex bars in the lineup and they give you maximum leverage for winding and unwinding heavy torsion springs. The length helps a lot when you are working on commercial-weight springs or if you just want more control during the winding process. Hex shape stops them from rolling off the ladder tray like round bars do. Same 5/8 to 1/2 inch profile as the 24-inch version, just longer. Check compatibility with your winding cone before you order.