The connector will be a standard configuration for RVs (except that there is one proprietary one, Smartplug).
Make sure to get one that is UL/CSA listed (stamped on the body). There are many that aren't and places like CW have plenty of them so beware. Extension cords, plugs and connectors aren't required to have UL/CSA listings. If you get a cheap one, you could end up regretting it. You get what you pay for but definitely shop around for the best price on a particular brand & part no. You want a connector that is a mechanically good fit and electrically, a tight connection with good contact with minimal resistance, and will keep water out. I wouldn't go cheap on something like this.
Do not get that says something like "connector for Marinco cord" as that's a giveaway that it's not a Marinco part. There are a lot of knockoffs and no-name brands out there. Can't go wrong with Marinco/ParkPower or Hubbell followed by Conntek, Furrion or Camco. Some connectors have a weatherproof boot. Marinco is the marine line of products and Park Power is the RV line. You'll probably fine premium prices on anything that is labelled "marine".
My recommdation is Parkpower and part number is 6364CRV and comes with a boot. A quick search comes up with Amazon as the best price at $63 incl. sh.
