This is Atlantic Water Garden's Black Media Bag. We have a large selection of Filtration/FilterFall Replacement Parts and other water features from Atlantic Water Gardens.
Manufacturer's Description
Atlantic's Media Bags are made with triple-stitched, heavy-duty netting and have a convenient drawstring to secure the media within your FilterFalls. Whether using lightweight media blocks, Bio-Balls, or heavy lava rocks, Atlantic's Media Bags are meant to last.