Matala Mat (Gray) 39" X 24" for Koi & Pond Filters The open highly aerobic tri-dimensional structure of Matala Filter Media promotes healthy water conditions and ease of cleaning in a wide variety of filter designs. This is simply the most effective, longest lasting, crush resistant filter material available today! Easily trims to fit Aquascape, Savio, American, Easy Pro, Laguna, Cyprio/Hozelock, etc. skimmers and filters just to name a few. A choice of densities allow for step-wise transition from mechanical to biological filtration. Filter Mat may be folded in center to facilitate shipping but will not impact function of the filter.