Using 100% food grade polypropylene as material, it contains no wetting agents, solvents, antistatic agents or binders; Lower density at the surface of the filter with progressively higher density towards the center. So the surface has a high dirt-holding capability and the inner layer keeps an accurate micron rate to remove small particles. The designs are various which i enclosed. OEM is also welcomed. Your special design will be understand by us, because we full of rich experience of manufacturing and exporting. Welcome to contact us ASAP.