Penn Plax 08225 Ammonia Remover Infused Filter Media Pad, 18 by 10-Inch FOR CLEANER WATER: the filter media material removes deadly ammonia from the water and leaves your fish less susceptible to disease and stress. MEASUREMENTS: made to be trimmed to fit your needs, the product is 10 x 18. MADE FOR ALL YOUR FILTRATION NEEDS: the filter media pad is made for freshwater aquariums as well as ponds. FULL LINE OF MEDIA PADS AVAILABLE: sold on Amazon, there are activated carbon, nitrate remover, phosphate remover, polyfiber, and polyfiber plus pads, by Penn Plax. Each sold separately. SHOP PENN PLAX FOR ALL YOUR PETS NEEDS: Penn Plax is a manufacturer and distributer of top pet supplies, who specialize in creating excellent pet products for animals both great and small.