The cat water filters are ONLY compatible with 84oz/2.5L Lite cat fountain/pet fountains shown in the pictures. (Filter size: 2.44 x 2.44 x 0.59in) Package includes a 12-pack of premium cat water filters. Each set is individually packaged and sealed to maintain high quality 1. Ion resin removes heavy metal ions and softens water quality 2. Activated carbon eliminates offensive odors 3. The non-woven fabric captures impurities and cat hair Every drop of water is filtered through multi-layer filtration to remove all contaminant, better-tasting water. To preserve the filtering effect, It's recommended to replace the pet fountain filter replacement 1-2 weeks in summer and 2-4 weeks in winter Please soak the cat fountain filter replacement for 5 minutes and rinse for 30 seconds before using to prevent the activated carbon dust, which won't harm your pets, from shedding into the water Brand names and/or trademarks are used here only for product description or identification of devices and/or device types MyfatBOSS 12 Pack Cat Water Fountain Filter, Cat Fountain Filters Fit Lite Cat and Dog Water Drinking Fountains, Pet Fountain Filter Compatible with 84oz/2.5L Automatic Pet Fountain