This is a TKO rear Ceramic engine bearing designed to fit recent Novarossi and RB Concepts engines that require the special 25.8 mm rear bearings. The bearing dimensions are 14mm inner, 25.8mm outer and 6mm thick. This bearing is open to allow lubrication to the bearings during use. This bearing will also fit any other .21 to .28 competition engine that uses the same bearing dimensions.
IMPORTANT: This bearing needs to be installed so that the balls face the rear of the engine (towards the backplate), for proper lubrication.