Eheim professionel 4e+ 350 electronic Eheim external filter professionel 4+. All Eheim external filters professionel 4+ feature an integrated self-priming system for quick filling of the filter container. The safety hose adapter is equipped with an easy-to-use locking mechanism, and for safety reasons, the adapter can only be released when the hose valves are closed. With proper handling of the Eheim external filter professionel 4+, your aquarium will always be supplied with the best water quality, which your fish and plants will thank you for with healthy and robust growth. You will enjoy a clean and clear aquarium. When the filter media becomes dirty and the water flow decreases, you can adjust it at the extender if necessary. This way, you won't have to intervene immediately and can gain a few extra days before the next cleaning of the filter media.