Ultilitrack sliding bed extender with brackets. I'm a picky buyer myself, so here's some additional detail. Good used condition with a couple scratches (see pics). Paint is original, but seems "splotchy" in places. Look closely in the pics. You may or may not even notice this.
Can disassemble for shipping (I'm in Kansas City). $100 + shipping from 66223. Will consider trade / partial for KC step rails or overhead rack.