BFSK vent and purge filters, sizes 25 to 125, combine air filtration and dehumidification in hydraulic systems. With special filter materials and water adsorbent, they minimize corrosion and filter fine particles, with moisture adsorption capacity. They offer options for check valves and adapter plates for ventilation control. They operate between 0°C and 85°C, with connections from G 3/8 to G 1 1/4.