10 Sets=80 Skateboard/Inline Skate Black Bearings work with Roller Hockey Rollerblades Too Yellow Seals & Nylon Cage 608-2RS Black Skateboard are Deep Groove Radial Ball Bearings, Bearings Work in RollerBlades and Scooters, bearings have nylon cage that would make them faster and they are blacked, bearings have 2 Removable yellow Seals, Bearings are made of Chrome Steel, each bearing has 2 Removable yellow Seals to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with oil.