The JW? Pet Clean Cup Feed & Water Cup is easy to attach to any bird cage. It can quickly be removed and refilled so your pet bird has a clean supply of food or water. The clear plastic hood acts as a guard that keeps debris inside the cage and doesnt block visibility so that your pet bird feels comfortable and safe placing its head inside to eat or drink. This easy-to-clean pet bird accessory fits all bird cages, including vertical and horizontal bars with a clever screw-on design. The cup is easily twisted and lifted to remove it from the holder for quick cleaning. The cup is durable and dishwasher safe. The small size is perfect for parakeets, canaries, and other small birds. The medium size is great for cockatiels, conures, lovebirds and similarly sized parrots, The large size is suitable for larger pet birds such as parrots and macaws.