Replacement foam set for the Eheim Professional3e 450, 700 and 600T 4x Fine and 1x coarse filter pads for mechanical and biological filtration. The porous material becomes evenly soaked with water and traps large and small dirt particles. After a start-up period, purification bacteria, which provide biological decomposition of harmful substances,populate the specially structured foam. The fine and coarse filter pads are reusable many times over. To clean them simply rinse in aquarium waterand squeeze out, so that the bacteria cultures are not completely destroyed. Key features: Porous material traps large and small dirt particles Good colonisation conditions for bacteria cultures Reusable several times over To clean just rinse in aquarium waterand squeeze out Pack contents: 1 x Blue pre filter foam 4 x White fine filter foam