Material: carbonized cotton + filter sandChanges from 2 to 4 weeks..Although our fountain filter can last a long time, to ensure the best protective filtration for our animals, we suggest a change every 2 to 4 weeks.3 layers of protection.2 layers high tension cotton + activated carbon. Remove debris, absorb heavy metals, eliminate odours. Protect your small catti from unnecessary infections. Give them a healthier and tastier water juice!Size: 14x1.3cmRinse and face upward,️ Rinse the fountain filter for 10 minutes before use to remove charcoal dust. Please put the flat facade up to ensure the best filtration!1/4/6/8/10/12PC filter cartridgeContains