PTR-3 .50 -101853
PCI ProCAl PTR-3.50-101853 Track Roller Bearing 1/2" Rubber Coat 4-1/2" OD
What catches my eye is the sturdy casing on this Eaton product.
PCI ProCal PTR-3.50-101853 Track Roller Bearing 1/2" Rubber Coat, 4-1/2" 4.50 OD
You will find that Glasmasters items come with a warranty that shows they stand behind them.