Since B ... W built only foreign manufacturers, these filters are those of B ... W in every way. Built in the workshop at least. 50. For releasing just about 6 screws (the 1er very accessible), is a joke. The self-installation (am a layman) takes max. 10 minutes, but I will never go back. In the workshop, you sparrt lot of money, time and can it for 10 min Prefer to take his sweetheart for ice cream ;-)