61800ZZ Ball Bearing 10mm x 19mm x5mm 61800ZZ Shielded Ball Bearing, this is a popular size that could be used in many RC Vigor helicopters, RC Cars and Trucks and any application that uses this size 10mm x 19mm x 5mm, this bearing is made of Chrome Steel, each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearing is pre-lubricated with grease.