... OPEN,Z,ZZ,RS,2RS,2RZ2. bearing type:ball bearings3. Cage(Retainer):Brass cage,nylon cage,steel cage4. Quality level ... after confirming P/O6. Feature:low voice,high speed,long life7. Application:home appliances.low noise ... and high speed electric motors,auotomotive components,pups,machinery,Bicycle8 ... 10-280 K,/W33,K/W33 High Quality Cylindrical Roller Bearing