The Flo-Cell Drainage Cells are great for use in a wide variety of water feature applications, including intake bays, wetland filters, and Pondless® Waterfalls. Each lightweight cell is made from polypropylene and its durable construction is designed to support heavy loads. Flow-Cells provide an extremely high infiltration rate with 90% void ratio to prevent clogging and provide rapid draining and water flow. This versatile product can be used in a variety of ways, including on top of Aquablox, under liner, beneath waterfalls to catch debris, and even up against foundations when installing water features next to a building. Each cell measures 16″ by 24″ and 1.18″ thick.