Two efficient filter elements joined together on one core make up DualSep™. Compax®, a proven industry leader in particulate filtration with more surface area than its competitors and APEX®, the tapered coalescing element which keeps annular velocities constant across the entire height of the element. The annular space on the outside of APEX® gradually increases from the bottom to top of the element, keeping pace with the external gas flow as it exited the element.