Matala Filter Sheet/Media Mat (Green) 14" X 24" -For Koi Pond Filtration The open, highly aerobic tri-dimensional structure of Matala Filter Media promotes healthy water conditions Provides ease of cleaning in a wide variety of filter designs. Green Matala is the most versatile of the 4 standard colors of Matala Filter media. Versatile and durable. Lasts for many years -2-5 times longer than other media. Measures: 14" x 24" x 1.5" thick