The Duo is a two-in-one bobble feeder and 2 stuffable, freezable mini bowls. It's soft enough that your dog can play it as treats and kibble are released, hard enough to where you can fill it with food and have them slowly eat it. This is great for rescues because it's something they can actively work on and play with. We use this with our rescue, Olive, when she's restless and wants to play. Especially great for rainy days!