NEMA L6-20 Locking Connector Plug The Probe 100+ monitors are

The Probe 100+ monitors are designed to 120V Single phase Power Lines with a high degree of accuracy

If none of the LEDs are illuminated then the problem may be with the hardware

5 to 18mm diameter

Insert each wire into the appropriate wire terminals

NEMA L6-20 Locking Connector Plug The Probe 100+ monitors areNEMA L6 20 Grounding Locking Connector 20 Amps 250 volt 3 wires , twist lock connector UL standards and certifications . 385 . 930 cord range 16 8 AWG wire gauge Heavy duty construction for maximum safety and reliability in the most extreme industrial settings. Provide a cable of applicable ampacity, service and temperature rating suitable for the conditions of use and location. Technical Datasheet