Specification: Square: Condition: 100% Brand New Material: Activated Carbon+Cotton Color: Package Information: Package size: 13 * 8 * 13cm/ 5.12 * 3.15 * 5.12in Package weight: 85g Gift Box Packaging Round: Package Information: Package size: 13 *13*4cm/ 5.2 * 5.1*1.5in Package weight: 80g Gift Box Packaging Package Included: 4 x Cat water fountain filter (Optional) Features: Carbon Replacement filters catches hair and debris remove impurities and odor keep the water tasting fresh. Kindly Note: only use in pet fountain! Keep Your Pet Healthy: Each filter is composed of activated carbon ion exchange resin and non-woven fabric. They can filter hair heavy metals and improve the taste of the water so that pets can drink clean and fresh water all day which helps to increase water consumption and reduce the risk of urinary tract infections. Recommendations: To prevent the activated carbon dust (which will not harm your pets) from shedding into water please soak the filter in water for 2 minutes and rinse it thoroughly under running water before use. According to your pet s drinking frequency and the number of pets using the fountain change the filter every 2-4 weeks. Kindly Notice: Please allow 1-3cm error due to manual measurement and make sure you do not mind before ordering.