So I put the large castors on because my kegerator is going into a motorhome and large castors help with rolling and provide air flow. I was pretty disappointed to see that the bolts are so tiny, obviously they will shear and strip out if given a bump. Also seems very odd that the new King Keg design doesn't allow a uniform 4 corner mounting...along with the proper size fasteners. 3 wheels fit into the corners and 1 wheel is offset inside so that's where any tipping will occur. Wheels are good but the mounting sucks.