Love the utility of these, I have both types of rollers - bought flat at first but scratched my beautiful chrome and transparent purple paint job the first time I put the bar on, so I bought the return rollers. I chopped off the end of the cheap Bells of Steel mag-pins and they work perfectly to hold them in place. Also I put two layers of UHMW tape inside so they fit nice and tight to the rack, I have a metric 3x3 (74mm x 74mm).
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Build Quality