Filters made of polyester and fiberglass. Full corrosion and salt water resistance. Equipped with pressure gauge panel, manual air relief valve and water purge. Cover Ø 400 mm. Sand discharge opening Ø 200 mm. Suitable for filtration rates of 20, 30, 40 and 50 m3 / h / m2. Please inquire about other speeds. All filters in Europe can be equipped with a valve block. Models are available for 1m and 1.2m filter beds and can withstand pressures up to 2.5 and 4 bar.