8x16x5 is standard 1/8 bearing. however it is a waste to use ceramic bearings in offroad vehicles as dirt will destroy them as fast as any other bearings
Radek
V4 D8 - RX8, XERUN 4168SD
F1-09 - Tekin RS Pro, 17.5t Redline, 2S LiPo
Sakura Zero S - LRP, Saturn 20T, 2S LiPo
*EX-10 Eurus*