Engineered for highly compact assemblies requiring exact axial positioning, the MF84-ZZ is a premium miniature deep groove ball bearing featuring an integrated outer-ring flange. Outfitted with dual non-contact metallic shields (ZZ), it delivers exceptional defense against dust and debris while maintaining the factory-applied lubrication. Because the metal shields avoid physical friction with the inner ring, the MF84-ZZ ensures minimal startup torque and ultra-smooth rotation. This makes it an essential component for high-RPM, space-constrained 4mm bore applications, including precision RC vehicles, micro-stepper motors, and delicate optical instruments.