MC-4 is a standardized solar connection extender and is often used on solar panels. The MC-4 connector is also used as a solar extension cable to lead the solar cables from the panels to the inverter in strings (cable packages). With MC-4 generator connection boxes, you only have to plug the MC-4 connectors into the generator connection box and you are ready to start up without the hassle of stripping and connecting the solar cables. Here is an example (just click)