1. Ordinary level: Basic level. The dimensional accuracy is less than ± 0.05mm, and the rotational speed is less than 500rpm, suitable for low-speed and low requirement environments. Such as low-speed transmission equipment, casters, strollers, toy cars, etc.

2. Motor level: P0Z2 or above. The dimensional accuracy is less than ± 0.01mm, the feel is smooth, the speed is less than 6000rpm, the noise is low, and the service life is long. Suitable for motors, toy models, cars, power tools, pneumatic tools, telecommunications equipment, fitness equipment, sports equipment, etc.

3. Premium level: P6 or above. Dimensional accuracy less than ± 0.005mm, smooth feel, speed greater than 6000rpm, low noise, long service life. Suitable for fields with high requirements such as high-speed motors, high-speed models, instruments and meters, precision equipment, high-end toys, etc.