[ABEC-11]: Providing higher precision than ABEC-9. High quality chrome steel inner and outer races, premium grade balls, great speed ball retainer. Excellent spin time, low-friction, super-fast skate bearings. [Double Sealed Shielded]: Each shield bearing has two low friction rubber seals, which have good closed performance, can contain lubricant and effectively prevent the invasion of external foreign matters, protect the bearing and extend the service life of the bearing. [Application]: Used in skateboard wheels, roller skates wheels, scooter wheels, inline skate wheels, caster wheels, 3D printer, etc. [Material]: Made of good quality chrome steel, with smooth surface, fast speed and low noise. The sturdy cage evenly separates the balls to reduce fri.