This is a set if two replacement XRAY 12x18x4mm Rubber Sealed High-Speed Ball-Bearings, and are intended for use with the XRAY RX8. These high-speed ball-bearings have been manufactured specially for XRAY to provide a super-free, super-smooth drivetrain. These highest quality ball-bearings have been degreased and lightly oiled with AeroShell Fluid 12 oil, and are then fitted with special rubber seals for maximum smoothness, long life, highest tolerance and maximum performance.
These ball-bearings have more (and larger) balls inside the cage than the standard ball-bearings, making them much more resilient under heavy loads. The side covers are easy to remove for quick and comfortable servicing. These ultra-high precision ball bearings are designed to withstand all extremes at the track under racing conditions or even just fun racing and should be considered a "must have" item!