Note: When You enter search term "6303RMX" into eBay or Amazon, you will note the availability of OEM measurement bearings - 10X42X13. "6303RMX" is stamped to the OEM idler #2 bearings. I've powerful uncertainties about these being high quality bearings, such as the Koyo bearings labeled as currently being designed https://www.aaacollectionagencyinc.com/our_certifications.html