When assembling the non-medical Reusable Sports Mask (RSM) or replacing a filter you will need to manipulate the replaceable valves and/or set them aside for a short time. We recommend that each user has at least one set of Replacement Valves on hand should they become lost or damaged for any reason. Please do not attempt to pry open the hinged portion of the valves. Simply follow the “Open” arrow, twist, and pull apart to replace old filters and/or wash the RSM Mask.