XRAY XB4 Sealed Bearing Kit (6) 10x15x4 (6) 5x10x4 (4) 5x12x4 (4) 5x8x2.5 (2) 8x14x4 You are purchasing the bearings listed above.In many cases the bearing sizes may change depending on your particular model and the date that it was manufactured as well as different hop ups you may have installed. PLEASE DOUBLE CHECK you R/C before ordering to make sure you are get all the proper bearings. We try to keep the kits updated as best as we can. If you find a variation or mistake in our kits, please contact us so we can look into it.