This kind of "separators" are pretty expensive. I've been quotes $50ea. to fit my RediRack (warehouse palette racking). They are mostly used in places like HomeDepot and other renovation centers. You need a beam in the back to hang these "separators". There's few mfg. / suppliers in my neighborhood but you're too far from me to refer 'em. Look into classifieds, there's always places that buy/sell these rackings in lots so you might be able to find a place to get used ones at better price.