MADE FOR ALL FILTRATION NEEDS: Our Carbon Infused 10” x 18” Aquarium Filter Pads are made to be trimmed and shaped to fit your filtration needs. These pads are designed for freshwater and saltwater aquariums, as well as outdoor ponds! They’re also great for turtle tanks! CLEAN, CRYSTAL-CLEAR WATER: In addition to trapping loose particulate matter, these pads help to reduce harmful chemicals, toxins, foul odors, and to clear up discolorations, from your aquarium’s water. They help keep water inside your tank crystal clean! HELPFUL INSTRUCTIONS: Please rinse thoroughly with cold water before placing in filter. Never use soap, as the residual soap particles can harm your fish. For best results, replace filter media every 4 – 6 weeks. MEASUREMENTS: Overall = 10” x 18” SHOP PENN-PLAX FOR ALL YOUR PET’S NEEDS: PENN-PLAX is a manufacturer and distributor of top quality pet supplies, who specialize in creating excellent pet products for animals, both great and small.