Parkworld 886139 Generator Adapter Cord Locking 4 Prong Male NEMA L14-30P to 10-30R Dryer 3-Prong Receptacle (1.5FT)

Good quality now I get to use my dryer

you are back feeding a three prong (NEMA 10-30) outlet such as an older electric clothes dryer style plug. When these plug styles were "code" the ground a neutral were shared and the other two legs were both hot providing 220 volts - 110 on each leg. On most generators the large round three pronged "RV output" is only 110 volts, only one leg is hot. So when I initially used the RV plug on the generator to back feed my house, I was only getting power to light switches. I switched legs on the receptacle in the wall of my laundry room. I only got plugs. I bought this adapter, that allows both legs to get hot, and now have both receptacles and plugs. High quality too.

Awesome

I use this to charge the tesla using this adapter for the dryer plug:https://www.amazon.com/Parkworld-64286-Splitter-Generator-Receptacle/dp/B0BD2BP929There's also the longer one depending on how much length you need:https://www.amazon.com/Parkworld-886139A-Generator-Adapter-Receptacle/dp/B08RRTBL3B/