Take note: When you enter search term "6303RMX" into eBay or Amazon, you will see the availability of o.e.m measurement bearings - 10X42X13. "6303RMX" is stamped around the OEM idler #two bearings. I've strong doubts about these being excellent bearings, including the Koyo bearings labeled as remaining made in Japan https://mydirectoryspace.com/listings13192135/the-ultimate-guide-to-credit-recovery-agency-in-anaheim