Abstract: An adsorbent media has a pore volume/media volume of at least about 0.12 cc pore volume/cc media, a specific heat capacity of less than about 2.9 J/cc pore volume, and a pressure drop of less than about 4.0 inH2O/ft media at a superficial air velocity of about 500 ft/min, wherein the adsorbent media is in a concentrator system. An extruded honeycomb adsorbent media has a cell density of more than about 200 cells per square inch (cspi), % open area of at least about 50%, an activated carbon content of at least about 50% by weight based on total weight, and a pressure drop of less than about 4.0 inH2O/ft media at a superficial fluid velocity of about 500 ft/min.