EHEIM Fine Filter Pad (White) for Classic External Filter 2211 - 9 Total Filters (3 Packs with 3 per Pack) 9 Total Filters (3 Packs with 3 per Pack) EHEIM Fine Filter Pad (White) for Classic External Filter 2211 Completely neutral pad Fine phenol-free structure of this synthetic material traps tiny particles of dirt Should be used as last layer in your set up