Pond pressure filter. It comprises a 20/30-litre capacity container, filter materials, accessories and pipe-fittings for connections. PREXO is equipped with a Backwash System (water flow inversion), which allows convenient and rapid filter cleaning without having to open or dismantle the filter. The Backwash System is activated by turning a knob positioned at the top of the filter. PREXO is easy to conceal as it can be partially hidden below ground near the pond. Thanks to state-of-the-art technology developed at Newa laboratories, the PREXO filter will keep the water in your pond clean and crystal clear all year round.