the frame may have a smooth surface or it may be provided with grooves or similar to enhance the adhesion force of the rubber to the frame in one embodiment of the present invention the collecting channels within the circular module are functioning as gas flow ducts which do not comprise an inner metal element but are fully formed of the mouldable material in one embodiment of the present invention a pressure element in the form of a metal mesh of well defined geometry is described to have following functions reducing ohmic resistance by keeping the electrode in intimate contact with the diaphragm conducting electrical current from bipolar plate to electrode and permitting gas to escape from the electrode surface the pressure element of the present invention is resilient by resilient it should be understood that the mechanical and geometrical properties of the said pressure element e g a metal mesh are balanced with regard to flexibility and stiffness in order to press the electrode to the diaphragm at all operational temperatures and not deform during cell assembly the metal mesh has sufficient mesh opening to allow for non hindered passing of fluid in both horizontal and vertical directions while maintaining the mechanical function in one embodiment of the pressure element the pressure element is in the corrugated form the wording corrugated form should be understood as any wave form such as i a sinus wave or square wave fig6 shows a sinus.