Ball Bearings 8x16x5 Hyper 7 Kyosho Kanai Mugen 20 Bearings This is a popular size that could be used in many Radio Control Cars and trucks like Hyper 7 Kyosho Kanai Mugen and any application 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.