These Aquascape Designs bio falls filters pads that are used to replace the pads in the Aquascape Designs biofalls filter. Your biofalls filter should contain three of these pads. Since these pads only get rinsed off a few times a year, they should last for a few years. Bio falls filter pad size 17.5" x 20" If your biofalls filter is square in shape, this is the correct filter pad replacement. Aquascape Mini Biofalls Filter Pad Aquascape Mini Biofalls Filter Pad Aquascape "Super" Mini Biofalls Filter Pad ponddepot@msn.com Copyright - All World Rights Reserved Pond pumps, Pond Kits and Pondless Waterfall kits, Underwater Pond Lights. Aquaclearer Extreme bacteria and String Algae Buster and pond fish food. Pond Depot provides Do-it-yourself pond kits and Pondless waterfall kits delivered right to your home at great prices! Thank you for shopping at Pond Depot you online pond superstore!