Model, this filter is suitable for 2.5L, 2L stainless steel water dispensers. Triple filter removes dirt and hair from drinking water, as well as deposits and odors caused by chlorine and bacteria. All activated carbon filters are rinsed before use to prevent carbon dust from dissolving and entering the drinking water. Depending on how many of your pets drink from the fountain, change the filter after 2-4 weeks. Scope of delivery: 4 replacement fountain filters