Bel-Art Stainless Steel Vertical Support Rod for Poly-Jaque Plastic Lab Jack F18391-0001 (F18391-0002) This 46 cm (18") long stainless steel support rod attaches to the top plate of the Poly-Jaque lab jack to allow attachment of various clamps and other accessories The rod diameter is 7.9 mm (5/16") and is supplied with two hex nuts for secure attachment to the jack top plate This metal rod is electrically conductive