Suitable for Monkeys, Primates and other smaller Carnivores and Canines. This device contains a captive food ball only accessible from the front. By reaching in, the animal is able to rotate the ball causing food contained within the ball to be dispensed in limited amounts. The ball is not able to be removed by any animal, and can only be removed by a keeper via the rear access plate. Ideal for either hanging or tethered to the ground. Short version is 400mm long and the LONG is 600mm.