This feeder is special because you can put fruits or vegetables in it and is convenient for pets. A perch on the side allows the animal to stand up when eating. Made from bite-resistant materials, it is durable and hard-wearing. the animal will enter the feeder by accident, a safety lock is on the top to prevent it from happening. Excnt for parrots, birds, parakeets, etc. are not included. The measurement error allowed is +/- 1-3cm.