S608-2RS Sealed Ceramic Skateboard Bearing 8mm x 22mm x 7mm S608-2RS Bearing is stainless steel Sealed silicon nitride Ceramic Skateboard Bearing, double sealed,radial and deep groove ball bearings,S608-2RS bearing is made of Stainless Steel with Si3N4 Ceramic (Silicon Nitride) balls,S608-2RS bearing is closed with rubber seals to protect the bearing from dust or any possible contamination,It is ABEC-5 quality to ensure high speeds.