Abstract: A flow-field plate (101) for a polymer electrolyte membrane device such as an electrolyser or a fuel cell comprising an inlet on one side (102) of the plate and 5 an outlet (103) on the opposite side, a distribution array (110) including a plurality of linear channels (106), a first interface (104) between the inlet (102) and distribution array (110) and a second interface (105) between the distribution array (110) and the outlet (103), wherein each interface includes up to rn rows of baffles (107), where rn=the width of the interface hd divided by the baffle diameter hb, the 10 majority of the baffles in each row being set at a particular angle relative to the longitudinal axis of the linear channels (106).