OFNA 1/8 Scale Axle or Wheel Ball Bearings 20 Bearings 20 Wheel Ball Bearings, this is a popular size that could be used in many Radio Control Cars and trucks like the MBX R2, Monster Pirate, Titan, Hyper 7, MBX Pro, Dominator, Ultra MBX and anything that uses this size 8mm x 16mm x 5mm. Bearings are made of Chrome Steel, each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease.