Features: _x000D_ These miniature bearing are made of high quality steel and ceramic for low noise and long service life. _x000D_ Bearing with ceramic balls is better resistant to corrosion and rarely require lubrication. _x000D_ Bearing has a 8mm inner diameter, a 22mm outer diameter and a 7mm thickness. _x000D_ These 608 bearing are specially designed for inline roller skate to improve speed._x000D_ _x000D_ The lighter balls allow the bearing to spin faster, and uses less energy to maintain its speed. _x000D_ _x000D_ _x000D_ Specifications: _x000D_ Material: Steel(races), zirconia ceramic(balls) _x000D_ _x000D_ Inner Diameter: 8mm / 0.31"_x000D_ _x000D_ Outer Diameter: 22mm / 0.86" _x000D_ Thickness: 7mm / 0.27" _x000D_ Quantity: 16pcs_x000D_ _x000D_ _x000D_ _x000D_ Package Includes: _x000D_ 16 x Bearings 1These miniature bearing are made of high quality steel and ceramic for low noise and long service life 2Bearing with ceramic balls is better resistant to corrosion and rarely require lubrication 3Bearing has a 8mm inner diameter, a 22mm outer diameter and a 7mm thickness 4These 608 bearing are specially designed for inline roller skate to improve speed 5The lighter balls allow the bearing to spin faster, and uses less energy to maintain its speed