The BWT besthead filter head is an ingenious technical solution. It fits on every water filter from BWT water+more and therefore only has to be purchased once. Setting the bypass is simple, reproducible and safe. A non-return valve on the inlet side prevents water from entering the drinking water line. A corresponding valve on the outlet side seals off the filter from the consumer (e.g. the coffee machine). Both non-return valves close in the event of a sudden drop in pressure, which prevents leaks and makes it easier to change the filter without water escaping. The BWT bestflush air vent completes the duo that makes this technology unique.