I got the 7-pin for my CX-50 turbo, the 7-pin has a 12-volt circuit, a circuit for electric trailer brakes, and a reverse light circuit that a 4-pin does not. Just provides more versatility if you ever use a larger trailer/camper. You can also get a 7-pin to 4-pin adapter to use 4-pin trailers, so pretty much worth it to just get the 7-pin! https://a.co/d/jaa6Eui