SIGMA series LH - KH high efficiency filters meet the strictest requirements of air conditioning and ventilation systems where high levels of air cleanness are required. The filter medium is made of deep pleated glass micro-fiber paper fitted with corrugated aluminum spacers. The frame is available in two different materials according to the models: MDF wood for LH filters and galvanized steel sheet for KH filters. The filter medium is fixed to the frame with a polyurethane sealant, the frame is fitted with a single piece gasket. LF - KF high efficiency filters have a moderate pressure drop level, a high dust holding capacity and offer considerable mechanical resistance. They come in various sizes to suit a wide range of air flow rates.