Abstract: An air return bulkhead is disclosed which may be adapted to fit on differently-sized trailer walls around differently-sized trailer refrigeration units. The bulkhead includes an upper support panel with ridges or other discontinuities thereon. The discontinuities bound areas sized to accommodate standard refrigeration units, and a cutting tool may be easily guided along these discontinuities to form a space wherein the refrigerator may be fit when the bulkhead is mounted to the trailer wall. Also disclosed is a bulkhead which includes flutes and columns thereon wherein the ends of the flutes and columns may be removed by use of a cutting tool to allow the bulkhead installer to tailor the airflow into the refrigerator inlet as desired.