All Airaid Premium Filters use a synthetic filtration media called SynthaFlow. SynthaFlow is a synthetic nano-fiber material that traps the smallest dirt particles that ordinary cotton-gauze "performance" filters can't capture. Based on SAE standards, Airaid Premium Filters with SynthaFlow technology, capture almost twice the percentage of 2 micron particulates and more than six times the amount of 0.5 micron particulates than our competitor's filters.