The Wesbar trailer harness has a robust connector which fits well with the truck 4 flat connector. I particularly like the way it is wired: Green, yellow, two browns, and white. That is, this is a 4 flat connector but has five wires, if you include the white ground wire in the count: Makes it very easy to connect to two trailer lights. The rubber connector has a slight angle and is ribbed which make it much easier to grab and pull out.