I made my own
I know this isn't what you are asking about, but I made my own. I used 3"x3"x3/16" angle iron. I shaped it, welded it, and painted it black. I will make another, and powder coat it. I have my toolbox and headache rack attached to it. The reason I need to make another, is I need one that hangs over a little more. I'll use 4"x3"x3/16" next time.
I'll make a deal if anyone wants the one I have. It attaches to the bed with bolts in the inside, and not down throught the top of the bedrails.
I had plastic on my Y2K truck. I got them from 4 Wheel Parts Wholesalers. They were okay. Same problem as stated above with the tape not sticking too well at the corners.
SOLER