Deep Blue Professional ADB41002 Super Activated Carbon Media Pad, 18 by 10-Inch Super activated carbon cut to fit media pad traps micro and macro organic particles, foreign debris and excess fish food For use in custom sumps/refugiums, hang-on filters, prefilter boxes and more Safe for both freshwater and marine aquaria Absorbs odors, discoloration and toxins Measures 18-inch length by 10-inch width