10pcs MR84-ZZ 4 x 8 x 3mm Miniature Metal Shielded Sealed Groove Model Ball Bearing
Features:
Bearings reduce friction by providing smooth metal balls or rollers and a smooth inner and outer metal surface for the balls to roll against. These balls or rollers "bear" the load， allowing the device to spin smoothly.

Specifications:
MR84-ZZ
Size: 4 x 8 x 3mm（Inner Diameter x Outer Diameter x Thickness）

Package Included:
10 x Bearings