Each filter pad set is good for approximately 5 gallons of beer when the beer has been filtered by the previous size pads or you are starting with the rough filters. These pads are not designed to be back flushed or reused.  They should be used in one session.

Rough pads will provide between 5.0-7.0 Micron filtration.

Polish pads will provide between 0.5-1.0 Micron filtration.

Sterile pads will provide between 0.3 - 0.5 Micron Sterile filtration.  The Sterile 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 a cartridge filter can do so.