Stiffner pieces for mounting larger items to our extra long 14 inch Slider Carrriage. Greater stiffness and rigidity suitable for longer travel BS-80 Belt Sliders. By adding this Stiffner subassembly, your BS-80 Slider Rail will be widened to 14-20 inches, compared to our standard carriage width of 3.8 inch. Also included are matching holes for mounting a 2nd Belt Slider at 90 degrees.