For use with our FIL45 series of plate filters. These pads will provide between .3 - .5 Micron filtration. This pad is the right choice when you want to promote sterility in the bottle, although do please note that the pad does not remove 100% of bacteria - only an absolute rated .45 micron or less cartridge filter can do so.  Then why do we sell this pad? Some experienced winemakers who are familiar with their wine and who do not have a cartridge filter use this pad to remove most ml bacteria, making it more unlikely that an unwanted ml fermentation takes place in the bottle.  ,,Each filter pad set is good for approximately 5 gallons of wine when the wine has already been filtered by the polish pads. These pads are disposable.