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 will be appreciated by your fish and plants through their healthy and robust development. You will enjoy a clean and clear aquarium. When the filter media becomes dirty and water flow decreases, you can adjust the extender 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.