Unbound Solar's dual MC4 cable extensions include two cables -- one with a male MC4 connector and another with female MC4 connector. Dual MC4 cables are used to connect a solar array to a grid-tied inverter, combiner box or anything which requires MC4 connectors for the solar array and bare copper wire at the opposite end. This 100 dual cable extension include a 100 long cable with male connector and bare copper; and a 100 long section with female connector and bare copper. Dual cable extensions are typically used to connect a string of modules to a gridtie string inverter, with MC4 connectors for the solar array and bare copper wire for connecting to the inverter, disconnect or combiner box.