NU-CORD 50M30F Rv Dogbone Adapter 50-Amp Male 30-Amp Female
This adapter allows you to plug your 30 amp rv to 50 amp service at campgrounds. You won't always need it, but you may find that the campsite you have chosen only has 50 amp. There is also one for 50 amp rv's to connect to 30 amp service. Find out what you need before purchasing.