I have seen the ones that plug into a receiver. They work great off road dealing with articulation differences between rig and trailer. My uncle has one that he tows jet skis to the river. We will womp the truck back into secluded beaches and launch the skis from where ever we want. My other buddy has an old cj and tows an off road trailer with tent and all and made through the rubicon with it, so definately stout and hold up well. As far as an H3 towing something off road, maybe a tent trailer max or single cycle trailer.
