XIANQI Features: The steel cage evenly separates the miniature ball bearings to reduce friction, vibration and noise SealingEach miniature ball bearing has two low friction single lip rubber seals Material: Deep groove bearings made of carbon steel, durable and resistant to deformation under heavy loads Application: Double shielded ball bearings very suitable for skateboards, inline skates, roller skates, scooters and other skating applications, also can be used for 3D printer hub bearings, CNC, etc waterproof: These bearings for skateboard are waterproof, dust and dirt proof and will keep your wheels rolling Description Deep groove bearings are made of carbon steel, it has durability and resistance to deformation under heavy loads. The protective covers on both sides of the bearing prevent dust from entering. Double shielded ball bearings are suitable for high-speed operation. Pre-lubricated and easy to maintain. Features Miniature ball bearings -Color: Red. -Material: Carbon steel. -Size: Inner Diameter: 0.7 cm/0.28 inch. Outer Diameter: 2.2 cm/0.87 inch. Height: 0.8 cm/0.31 inch. Matters needing attention: 1. Keep the bearing and its working environment clean, even the small dust that can't be seen by eyes will bring bad influence to the machine tool bearing. Therefore, to keep the surrounding clean, so that the dust does not invade the bearing. 2. Careful use, in the use of the bearing to bear a strong impact will produce scars and indentation, become the cause of the accident, in serious cases, will crack, fracture, so we must pay attention to. Package Including 10 x Miniature ball bearings