【Scope of Application】-- Pack of 10 filters fit for 81oz/2.4L Comsmart, Wonder, etc pet fountains (NOT for Catit FOUNTAIN, please double check size before purchase.)【Triple Action Fountain Filter】-- The pet fountain filter is composed of a cotton layer,activated carbon and an ion exchange resin.They can filter hair, heavy metals, and improve the taste of the water so that pets can drink clean and fresh water. All materials of the filter are certified by SGS.【Note】-- Please rinse the filter 3-5 minutes thoroughly with water before use to remove the charcoal dust and to activate the resin! Please put the flat facade upward to ensure best filtration!【Easy to use】-- This pet filters is easy to install,remove and replace. And we advise you to replace the filter every 1-2 weeks, water pump also needs to be cleaned every 3 days to ensure the clean of drinking water【100% Satisfaction Warranty】-- Individually packaged and sealed to maintain high quality, 30 days money back. If you have any questions, please contact us any time! We will strive to help!