【Well-Fitted & Easy to Clean】This cat water fountain filter is perfectly compatible with the 2L, 2.5L (67oz, 84oz) cat water fountains shown in the picture. (Filter Size: 10cm/3.9", Center Hole Size: 2cm /0.79"). Please make sure this cat fountain filter is compatible with your cat water fountain before purchasing. 【No Plastic Shell】Our water fountain filters are made of high-quality cotton layer, activated carbon and ion exchange resin. The cotton layer replaces the plastic shell and is more environmentally friendly. It can better filter water as well as soggy food that may end up in the pet fountain. 【Keep Your Pet Healthy】-There are some chemicals in the water that affect the health of pets, this pet fountain filter can help remove waste from the water and provide clean and fresh water for your pet, reduce the risk of urinary tract infection; it is very important for the health of pets. 【Cat Fountain Filter Individually Wrapped】-Each cat fountain filter is individually wrapped,