USED INSIDE AND OUTSIDE THE CAGE --- You can fix it outside or inside the cage according to your own needs. If your pet is naughty, it is suggested to install it outside the cage. And you can easily turn the water dispenser on or off to clean and refill it. NO NOISE --- This automatic pet water dispenser adopts gravity flow design and can control the amount of water to prevent overflow. It does not make annoying noises while your pet is drinking compared to water bottles with ball bearings. The quiet design allows you to have a quiet night sleeping environment. LARGE CAPACITY --- 500ml/17oz large capacity, you no longer have to worry about your pet not having enough water to drink if you are not at home all day. This water bottle is the perfect size for rats, hamsters, guinea pigs, small ferrets, dwarf rabbits and other small pets. · SAFE --- Made of non-toxic and durable PP plastic. Compared with traditional water bottles and bowls, our hanging water fountain provides your pet with a