5 micron filter bags.  Comes with 10 bags.  Collect even the smallest debris with these bags.  Works with the 4000, 4001, and the 8000 filter paks.

We recommend 25 micron if using plastic media and a 15 micron if using ceramic media. All filtration systems come with a 15 micron if you'd like to use the same filter bag.

A 5 micron is the smallest hole size and lets less particles through. A 100 is the largest hole size and lets the most particles through.