Super -fold filtration: 1. Pre-filter to filter hair and other impurities. 2. High-density mesh to filter small impurities in water. 3. exchange to filter heavy metal impurities. 4. Activated carbon to filter odor and small molecular impurities. 5.8D filter cotton Filter fine molecular impurities. Bring the best water quality to your pet. Replacement cycle: The best replacement cycle is once 4-5 days. [More Professional Filtering] The water filter can effectively filter impurities, purify and soften the water quality, and prevent the water pump from clogging. High Quality of Filters: Each filters is composed of cotton exchange resin, activated carbon and cotton mesh.They catch hair and debris, filter heavy metals, water quality, which is more healthier than other filter materials. Advise: please soak the pet filter in water for 2 minutes and rinse it thoroughly under running water before to prevent the activated carbon dust from shedding into water. pcs individually packaged and sealed to maintain high quality. Color: white + blue Material: Cotton Package Contents: 5 x Water Filters Only the above package content, other products are not included. Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.