Eheim External filter professional 4+ 250

Strong performance, optimal energy efficiency, pleasant running smoothness, intake assistance, safety hose adapter, and many other advantages have been adopted from the professional 3 series. The highlight is the new "Xtender": When the filter media are dirty and the water flow decreases, you can simply adjust it using the rotary knob if necessary. This way, you don't have to intervene immediately and gain a few extra days before the next cleaning of the filter media. The biological filtration remains intact due to the redirected water flow.