This is set of two replacement 10x15x4mm bearings for the XRAY T2 1/10th scale touring car. These bearings are used to support the differential. Top-quality professional ball bearings for a super-free, super-smooth drive train. These highest quality ball bearings are fitted with special rubber covers, and are degreased and lightly oiled with Aero Shell Fluid 12 oil for maximum smoothness, long life, highest tolerance and maximum performance. These ball bearings have more (and larger) balls inside the cage than the regular ball bearings, making them much more resilient under loads. The side covers are easy to remove for quick and comfortable servicing.