lawn Mower Bearings Reduce Friction and Heat,Uniforn Force,Life time Lubrication,100% Noice Test OEM Replacement Bearings Precision Radial Single Row Ball Bearing , Bearings are made of Chrome Steel and can rotate up to 15000 rpm, each bearing has 2 Premium Rubber Blue Seals to protect the bearing from dust or any possible contamination, Our bearings are manufactured for engineered shafting, bearings are pre-lubricated with Mobil Polyrex grease EM These bearings are ABEC 3 Quality