The BWT E1 single-lever filter is a protective filter with innovative comfort and hygiene advantages. Replacing the hygiene reservoir, which is the filter cup with the filter element, is so simple that the consumer can do it themselves in just a few seconds. Unlock the safety mechanism, which simultaneously shuts off the water. Pull up the lever to automatically eject the hygiene reservoir. Insert the new hygiene reservoir. Close the lever. Lock it. Done. And all of this in less than 30 seconds. In this way, BWT has mitigated the hygiene risks of conventional filters, as water-contacted parts are no longer touched. Additionally, the E1 prevents splashing water during the replacement of the hygiene reservoir, and the water line does not run empty.