Look at the filter material
　　The main filter material of air filter element is filter paper. Nowadays, filter paper of filter element is mainly made of domestic paper and imported paper. Both domestic and imported paper have good filtering performance. In general, the color of the filter paper of the genuine filter element is uniform and the paper surface is relatively flat. But the inferior filter core filter paper color is not unified, the paper surface hair, the quality of a material is very poor.
　　This paper is sorted out by dongguan oneness filtration technology co., LTD