The filter has excellent resistance to chemical including corrosive vapour and most acids except phosphoric and hydro solvents which have little or no effect. These have excellent electric qualities, they neither absorb moisture, swell, stretch nor undergo chemical change through contact with moisture. Filter medium fabricated from fire proof 100% micro fiber glass paper pleated with aluminium/cadmium plated mild steel with exclusive plastic base adhesive. Continuous neoprene sponge rubber seals are provided on filter frame for effective sealing . The filter has a filtration efficiency of upto 99.97%, particle retention >0.3 micron and can operate in temperature upto 150° C intermittent 121°C continuous and 100% relative humidity. The filter are tested by the DOP test methods, the most accurate and stringent test.