Abstract: A unique filtering face-piece respirator or mask that is constructed of filtration media capable of sub-micron particle absorption or filtration. Utilizing existing and broadly available low cost media, the mask is patterned from a single sheet of material. It is constructed in a manner that creates an adequate seal as it fits snugly to the user's face, creates structure to ensure a low volume air gap, and deploys unique vertical pleats to increase surface area in order to decrease pressure drop across the mask. Specifically, the design enables the user to inhale and exhale with a pressure drop below 0.4 inches of water at elevated breathing rates of up to 110 liters per hour. Valve design and positioning enable more than 90% of used air to be exited the mask.