... Anti-pollution: it can prevent greasy dirt, dust, etc., as well as control mould, scale, yellow urinary scale on the toilet stool ... net.Shapes: porous foam photocatalyst purfication net, hexagonal structure of aluminium cellular photocatalyst purfication net, porous metal photocatalyst purfication net ... photocatalyst filter, composite photocatalyst filter, and so on 2013 new style photocatalyst filter