Yeah, the website isn't clear. But, it's identical to the switches that are currently in the trailer - same brand, housing, size, shape, everything - except for the illumination part. Swapping the switch itself is a snap - literally. Remove the white one from the housing by pushing it from the back, and snap the new one in.
I guess what threw me was the third terminal - not understanding at the time that the light within the switch won't work unless that terminal is connected to a ground wire.
"You can't buy happiness, but you can buy an RV. And that is pretty close."