Leviton black switch power supply cord #SF-522-Q17/Rev X. I believe that these were originally manufactured by the Electricord Division of Leviton for Line Master as an accessory to their foot pedal switches. Features include:
Used to control the output of a receptacle using a switching device such as a foot pedal or similar switch. The control device (foot pedal, float switch, switch, etc) is wired into the stripped wires of the pigtail end; the appliance to be controlled (e.g., a pump, light, motor) plugs into the piggyback end, allowing the switch to regulate power to the appliance
The hot side of the plug is activated by connecting and disconnecting the white and black wire leads with a suitable switch.
Typical uses of a switched piggyback cord are: foot-pedal control, float switch, timer, or thermostat.
8 feet long, 14 gauge stranded wire, 3 conductor, SJT black outer jacket with attached 3-prong series plug.
