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 24-inches by 39-inches 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 1.5-inches thick and extremely easy to maintain, only needing to be cleaned periodically. For best results we recommend combining different densities to maximizing mechanical and biological filtration. Aquascape is passionate about the products we produce, providing unique products, designs, and features that stand above the competition.