K9 self-propelled artillery has been exported to account for half of the world's self-propelled artillery market. We have developed and are supplying filters for the engine intake air purifier of K9 self-propelled artillery. We have all the performance testing equipment for the filter for the engine intake air purifier of the K9 self-propelled howitzer, and verify the quality of the product every year during production. It has low air resistance, high filtration efficiency, and does not break even at minus 40℃ and 120℃.