To be honest, I don't even remember why I ordered these, but I only have 10 pounders. They do the job and are sized with the rest of my bumpers so work just fine.
Was purchased second hand with a pile of other items, otherwise this is a little set up intensive. Thankfully I have spare plates to keep it in, but otherwise it would be more burdensome.
My Hercules hold DIY setup involves backing my truck onto a small ramp while adding an attachment to its hitch and to a static point in the gym (loaded weight tree). Great value for the cost, but it takes someone helping to safely operate.