Semi-metal High metal fiber(iron fiber, steel fiber, etc) content 鈮?0% Advantages: long life-span, high load, low cost. Disadvantages: low coefficient of friction, noise, wear to the brake disc, rapid aging of brake components. Less metal Lower metal fiber( Iron fiber, steel fiber, etc.) content<30% Advantages: high performance, good low speed, more suitable for European and American vehicles, friction coefficient is 0.4~0.42 Disadvantages: noisy, short life, dusty. Non-Asbestos organics(ceramic formulation) NAO Mainly use glass fiber, rubber, graphite and other organic substances as reinforcement materials Advantages: low noise, less dust, friction coefficient 0.36~0.38. Disadvantage: high temperature and high load characteristics (fading) are not ideal. Performance indicators related friction materials The coefficient of friction is the ratio of the frictional force between two surfaces to the vertical force acting on one surface. This coefficient is one of the important indicators to measure the braking effect of brake pads. Friction Level EE grade: 0.25-0.35 is suitable for European and American cars. brake pads are relatively large and the friction coefficient is relatively low. 6. If there is sound, the brake pads are in a semi-slip state at the moment of starting, so that the automatic transmission car has a unique sound, and there is no manual transmission. This kind of sound is a normal phenomenon when the brake pads are in a semi-slip state.Auto Brake Systems for sale website:http://www.masuma.com/auto-brake-systems/