Observe: If you enter search term "6303RMX" into eBay or Amazon, you will notice The provision of o.e.m size bearings - 10X42X13. "6303RMX" is stamped within the OEM idler #2 bearings. I have powerful doubts about these currently being high-quality bearings, such as the Koyo bearings labeled as becoming created in Japan mainly because this bearing