Dan Beluscak Think you gave it away when you said back window knocked out !! Gin poles are heavy pipe attached at the edge of the bed.They extend out behind and are attched at the top with an "A' shaped heavy steel fork that goes into the pipe. Then your cable goes thru a snatch block hanging on that "A" shaped bracket. The "gin Poles are then chained to the headache rack about cab roof high. When you go over like a river levee the gin poles can upset and throw stuff thru the back glass of the cab !! That is why you chain them down. All oilfield guys learn this ! A snatch block (pully) is made so you can easily take the cable out of it.