World Champion ACER Racing 4x8x3mm Flanged Ceramic Ball Bearings.  These are two 4x8mm Flanged ceramic ball bearings also known as a size MF84 ball bearing. Diamond polished Silicon Nitride (Si3N4) Balls, HSR cage technology and sealed on both sides. Lubricated with lightweight and 100% synthetic ACER Racing SIN Oil instead of thick grease for super fast and super smooth action.

Price is for TWO bearings as shown in the photo.