10-Pack 6x10x3 Sealed Miniature Bearing Outer Diameter - 4mm Each bearings has 2 rubber-sealed

Each bearings has 2 rubber-sealed or metal to protect the bearing from dust or any possible contamination

Ceramic Balls are the highest standard of balls that can make your bearings live at least 5 times more than any other bearings with Premium ABEC-5 quality

Bearing Outer Diameter: 215mm

the NU311 inner diameter is 55mm

5 sets each set has 8 bearings inside a gift box

10-Pack 6x10x3 Sealed Miniature Bearing Outer Diameter - 4mm Each bearings has 2 rubber-sealed6 x 10 x 3 Sealed Ball Bearings Lot of 10 Bearings 6 x 10 x 3 Sealed Ball Bearings, Made from high strength chrome steel for durability and performance, each bearing are rubber sealed from both sides to protect the bearing from dust or any possible contamination, additionally, these bearings come pre lubricated with grease for smooth operation. 6 x 10 x 3 Ball Bearings Deep Groove Ball Bearings Closures: Two Rubber Seals Lubrication: Pre lubricated