You can put food in from either side, and you can "shake" the food out if there's any left in there. There's a cool dial on one side that you can set to either "min" or "max", so your dog can get the food out easier, or for more of a challenge. For beginners, the instructions say to leave the dial switched to "Max" so they get more food out with less effort, and also to leave the other side open as well. That way they will learn that if they roll the ball, they'll get their food. As soon as they catch on, you can close one side... then switch the dial to "min" and it will be more of a challenge. Keeps your dogs brain working and helps them have fun. We are LOVING it!
