Matala Mat (Blue) 24" X 39" for Koi & Pond Filters The open, highly aerobic 3 dimensional structure of Matala Filter Media promotes healthy water conditions and ease of cleaning in a wide variety of filter designs. Provides ease of cleaning in a wide variety of filter designs. Blue Matala is the 2nd densest (next to gray) of the 4 standard colors of Matala. Versatile and durable. Lasts for many years -2-5 times longer than other media. Measures: 24" x 39" x 1.5" thick