Providing proper filtration for your pond is absolutely crucial! The Aquascape Low Density Filter provides efficient mechanical and biological filtration for your pond. The filter mat measures 61cm x 99cm and can be easily cut to your desired size and shape using a serrated knife, allowing for installation in a wide variety of skimmer boxes and filters. Aquascape Low Density Filter Mats are 3.8cm thick and extremely easy to maintain, only needing to be cleaned periodically. For best results we recommend combining different densities to maximising mechanical and biological filtration.