ABEC35 MR115 Type-X Ball bearings
ABEC35 has introduced the popular 5x11x4mm ball bearings in Type-X specifications, types XSO and XCO. Both feature non contact rubber shields and come lightly oiled and ready to use. Type-X ball bearings are specially made for R/C cars with dedicated radial play and lubrication and are very low friction, withstanding alignment issues found in composite/plastic parts. Suitable for Tamiya, HPI, Traxxas and Duratrax cars, bulk packages and ball bearing sets are now available.
Source: ABEC35 [abec35.com]