Tamiya has released Ball Bearing Set for TT01 / TT-01 under category #53497 Tamiya - Ball Bearing Set for TT01 / TT-01 Chassis These are Ball Bearings from Tamiya. FEATURES: Usable with Tamiya #39;s TT-01 chassis cars (Expert Built) Ball bearings are the most essential part for tuning up your R/C car. Enables heightened top speed and longer component life. Sealed, stainless steel ball bearing set. #1150 bearings are used with spur gears. #1280 bearings are used with differential gears. INCLUDES: (12) #1150 5 x 11mm Ball Bearings (4) #1280 8 x 12mm Ball Bearings REQUIRES: To replace bearings refer to TT-01 chassis instruction manual