The low density Aquascape Rigid Filter Media Mat offers exceptional mechanical and biological filtration for a variety of different pond environments. The mat is constructed of incredibly coarse fibers and measures in at 24 inches by 39 inches and is 1.5 inches thick, effectively trapping many large pieces of particulate matter or debris such as leaves and sticks. The Aquascape Rigid Filter Media Mat can be cut to specific shapes and sizes which makes it ideal for use with a variety of different skimmer boxes and filter applications. The high quality media mat is durable, easy to maintain and only needs to be cleaned periodically. Completely safe for all aquatic plants and animals. For optimal results and improved water quality, combine various densities of filter media mats.