It is built with galvanized sheet metal frame, filtering media in galvanized wire tubular sock, 48mm thickness, contained by two welded galvanized nets. The filter is used in the presence of dust and large pollutants suspended in the air or in case of filtration of oily mists. It may be installed as pre-filter in combination with the ePM10 60% (M5), ePM1 55% (F7) or ePM1 80% (F9) filters, located on the room air return side.