Inside the aluminum case of the PX/PS series is the capacitive element, consisting of an anode and cathode foil wound with a separator sandwiched between them, and the winding end taped. In addition, the element is filled with sufficient conductive polymer electrolyte. The element is then stored inside the aluminum case, and sealed with a rubber seal. The rubber seal is also produced at Chemi-Con, and is composed of a variety of technologies to improve air-tightness.