This Beckett Pond Underlay is great for any pond, container garden, waterfall, or swimming pool. This underlayment ensures that things such as rocks, sticks, and rodents do not at all damage your liner, ensuring a long and healthy life for your pond and all of it’s parts. This underlayment liner is made of polypropylene, which is great for fish ponds as it creates an ecologically friendly environment for flora and fauna alike. The flexiblity of the material allows for creative design. No maintenence required for lasting beauty. This makes a great base foundation for any pond. This precut piece measures 6 feet by 12 feet, which covers 72 square feet of floor space with ease.