2000 Ford Expedition Eddie bauer, 5.4L, 4x4, tow rating?

I use these mirrors on my '04 Expy (attached from the top of the mirror, not the base). There is some slight vibration at highway speed, but nothing that makes viewing difficult. I was expecting a whole lot more, actually.

Been using them for 2 seasons now, still pleased with the view they provide.

Aero2 Towing mirrors.