Flow L/min: volumetric flow rate. Set to ~60 L/min for a standard filter holder area of 100 cm^2.
Resistance (mm H20): Resistance (pressure drop). A higher number means it will be harder to breathe. A typical N95 mask has a pressure drop around 9 mm H20, max of 35mm H20.
% Penetration: percentage of test particles that passed through
% Efficiency: percentage of test particles that could not pass through. An N95 mask has a minimum efficiency rating of 95%.