Heavy-gauge wire coiled tightly around 49-strand aircraft-type wire rope and heat treated. Has unequalled strength and the right amount of flexibility. So tough it carries a one-year warranty against defect or breakage. Flexicore Patent Nos. 2,244,735 and 2,849,870. General Pipe Cleaners Flexicore® Replacement Cable, 5/8 in Dia, For Use With: Floor Model Machine, Steel, 100 ft Maximum Run