Observe: Should You enter key phrase "6303RMX" into eBay or Amazon, you will note The supply of o.e.m measurement bearings - 10X42X13. "6303RMX" is stamped around the OEM idler #two bearings. I have potent doubts about these being excellent bearings, including the Koyo bearings labeled as staying created in Japan https://aaacollectionagencyinc.com/our_services.html