High precision: After high-precision instrument testing, to ensure that the error is minimized, high precision, lower operating noise, and higher speed Double cover seal: Both sides of the bearing are equipped with non-contact detachable protective covers, which can achieve the best lubrication effect, while preventing water and dust from entering, ensuring the speed and service life of the bearing High-quality and durable: Made of high-quality bearing steel, with a load-resistant high-hardness shell, rust-proof and wear-resistant, solid and durable, which can ensure safe operation Exquisite packaging: It is packed in a translucent cylindrical plastic box, which makes the bearing very convenient to take and easy to store to reduce bearing loss Widely used: A total of 20 bearings, inner diameter 8mm, outer diameter 22mm, thickness 7mm, suitable for skateboards, inline skates and scooters, etc