S697ZZ Shielded Ball Bearing Premium ABEC-5 Quality with Si3N4 Ceramic Balls 7mm x 17mm x 5mm S697ZZ Shielded Ball Bearing, bearing is Premium ABEC-5 Quality with Si3N4 Ceramic Balls, this is a popular size that could be used in many fishing reels, 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.