VEVOR 50Ft 50 Amp RV Extension Cord Durable Premium Power Cord RV 26.5mm Wire Diameter Extension Cord Copper Wire RV Cord Power Supply Cable for Trailer Motorhome Camper with Handles

Yes. Physically any number of cords can be connected together. What you need to consider when combining cords is the amount of voltage drop you will tolerate. That depends on the wire gauge and length and the current drawn by the load. Using the calculator at https://www.southwire.com/calculator-vdrop with 100 feet of AWG 6 copper wire shows a voltage drop of 1.84% at the rated current of 50 amps. A voltage drop of 3% or less is generally satisfactory for most applications. Even 3 cords have <3%

It can be connected. The plug-in can be mutually inserted, but the current should be taken into account. If the current is large, it is not recommended for it may lead to overload too large. The gauge (thickness of the wire) is designed for the amperage (current) running through it. If you connect two cords together, you will cause more resistance in the wire and generate more heat.

The ground wires in this cord are green.

We do not recommend using two extension cables connected together.

only have needed once in 4 years but when you need it you have it.