Aquascape Non-Woven Geotextile Underlayment is used to protect pond liner from rocks, roots, and other sharp objects that may damage the liner. The underlayment is lightweight, spreads easily, and has a non-slippery surface, making installation quick and easy. The soft, non-woven geotextile made from polypropylene also allows for any gases to escape properly, rather than becoming trapped beneath the liner. Protects pond liner from rocks and other sharp objectsLightweight and spreads easilyNon-slippery surfaceAllows gasses to escapeProvides years of trouble-free protection The rolls do not qualify for free shipping.