Trailer adapter question?

Anyone know what vehicle this trailer plug comes off of? Its on my 91 explorer and no one has one like it. The original 91 explorer has a square plug not the round like this one. This would be a drawing of what the adapter would look like, the 8 circles would be where the pins are. The closest I have found it for a 95 to newer F 150, but the side rail on the left is at a 45 degree to the top not the bottom. Any help would be appreciated as I need to find a new adapter as I lost the other one when towing my trailer last time.
Here is the drawing.

Tim, that could be one of the big pull behind camper type connectors with a constant 12 volt power supply and trailer brakes. Might want to check the parts department at a travel trailer sales company......

Thanks Dave, I think I may have figured it out by searching the net. I found a site that has 2 types for the Explorer, The square one that everyone has around here and a round one for the explorer with a tow package, I could not see the round one clear enough as the picture wasn't that great, ButI am going to check on that with our local trailer sales place tuesday. Hopefully they have it, if not I am going to rewire a new adapter in as I need to tow my car wed to the farm for storage until my garage is built.
Thanks again for the help and idea.
Tim