Thank you for viewing! ^^ This is a circulating water fountain for cats. Water flows from the flower petals, creating movement that encourages cats to drink. The flower can also be removed. I am selling this because I purchased a different one. Filters are sold separately, but it can be used without a filter. It holds a lot of water, so it's also recommended for those with multiple cats. It holds about 1.5L, but it makes a sound when the water level gets low, so you'll need to refill it. If you have any questions, please comment.