-- I remember when Stephan Tanner visited the club for a presentation a few years back. Even then I was impressed by the simplicity and durability of the mattenfliter design. I have yet to purchase any of the foam and therefore cannot speak personally to the performance of these filters, but I do not find it difficult to believe they are excellent.
Whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable - if anything is excellent or praiseworthy - think about such things. Philippians 4:8