Product review (3 stars): Three stars because its a GE product
Have GE dishwasher purchased before I stopped buying their stuff due to involvement with MSNBC and other stuff that just went against my grain.
The roller assemblies were fine, likely with Chinese inked "GE" on the bag.
When removing end caps it is best to first flex the the locking strip of metal on outside the rail outward before taking them out. I suspect they sell the end caps only as a result of the twist and pull only technique of removal.  Clearance may be tight so be careful of adjacent cabinet when prying strip out with old American or European steel, thin bladed screw driver.
New roller assembly appears nylon which may not degrade (yellowing) from the chemical bath that dishwasher parts get.
Installation was a breeze after cap removal. Re installing cap made easier by shaving a bit of an angle on nib that gets locked in so it can slide in more readily. Use needle nose pliers to bend locking strip back. The locking strip is what keeps the cap, roller and ultimately the rack from flying out of the rail.