This 48? trailer is white with black Canadian National ?SuperTherm? herald and black lettering. With sharp increases in costs of energy in 1980, there was considerable focus by industry on energy conservation. This insulated van has ?SuperTherm? 6 in. insulation floor, walls, ceiling, and doors and is part of series 715001-715114. Trailers were painted with the ?SuperTherm? herald in the 1980?s.