Originally Posted by JCL

Yes, those are surge brakes. The trailer includes a master cylinder attached to the hitch coupler on the trailer, so when the truck brakes and slows it activates the trailer brakes mechanically. If properly maintained, they work fine. I throw that in only due to your rental trailer scenario.

What they don't allow is any form of weight distribution hitch, or independent control of trailer brakes. But they do handle straightforward braking.