Material: Carbon steel. High durability and resistance to deformation under heavy loads. Double shielded: The bearing has shields on both sides to prevent lubricant ingress and the ingress of environmental debris that can reduce the speed and life of the wheel. Durable and low friction: The long plate bearing is made of bearing steel for durability, less deformation under heavy loads, low noise and low friction. Size: 8*22*7mm Works at 20-200C: resistant to high temperatures and able to work in a temperature range of around 20-200C. Can be used in many different environments. Wide range of use: These linear bearings are ideal for engines, machinery, tools, furniture, sports equipment, skateboards, scooters, toys, etc.