Ball Bearings 3/16" x 1/2" R3ZZ Metal Bearings Lot of 50 Bearings Lot of 50 bearings Ball Bearings size 3/16" x 1/2" x 0.1960", Metal Bearings 0.1875" x 0.5000" x 0.1960", this is a popular size that could be used in many Radio Control Cars and trucks, anything that uses this size 3/16" x 1/2" x 0.1960", Bearings are packed 10 bearings in one plastic tube. Bearings are made of Chrome Steel and can rotate up to 42000 rpm, each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease.