Features: brand new and high quality For better water quality, the filter element is replaced every 2-4 months, depending on the water quality and the number of pets. Made of environmentally friendly non-toxic materials, the filter helps ensure water quality and provides healthy and pure water to protect your pets for health. It is composed of cotton layer, activated carbon and ion exchange resin. It can effectively remove hair, remove heavy metals, and improve the taste of water, allowing pets to drink clean and for fresh water every day, helping to increase drinking water and reducing the risk of urinary tract infections. Reminder: Please rinse the filter with clean water before replacement. It is best to have a continuous and sufficient filter supply to ensure the water quality. Fit for PETLIBRO stainless steel for cat drinker. Package Includes: 4x Activated Carbon Filters 4x Sponge Filters Specifications: Material: Activated Carbon+Sponge Size: As The Picture Shows note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.