The Hydro Fleece was developed for use with the Lucky Reptile Hydro Drain clay substrate. It prevents substrate from seeping into the drainage layer while letting through water without problems.
Compared to solutions with nets or meshes the main advantage of the Hydro Fleece is that it also stops fine materials like soil from getting into the drainage layer. The fleece does not rot and can be easily cut to the desired size. To cover the floor in larger terrariums several pieces of Hydro Fleece can be arranged with a small overlapping area to achieve the desired coverage.