the ac-series filter is designed to remove oil vapor and odors. the activated carbon media will absorb residual vapors by causing them to adhere to the activated carbon grain molecules. the residual oil content is reduced to 0.008 mg/mg3 or less. the ac filters are installed post coalescing filter such as the c or che. they are equipped with a manual type drain. the element is comprised of a thick carbon layer covered by a fiber coating. the media is supported by stainless steel mesh screens.