MIL-DTL-13273 Cord, Electrical, \(Retractile, 2, 3, And 4 Conductor, Wd-9/U, Wt-2/U, Wf-4/U\)This specification covers 2, 3, and 4 cadmium copper alloy stranded retractile conductor electrical cords. These cords are insulated with a natural rubber compound encased in a Buna S or Buna S and natural rubber compound jacket which is vulcanized in a helical spring coil form to produce a cord which will extend and retract freely. These cords are designed for use on communications equipment at audio frequencies, with a temperature range of -0 to 60 degrees C for continuous operation.