This container is great! The bigger container is perfect size. We bought a 15lb bag of dog food and it fits perfectly. I would not recommend buying a bag that is more than 15lbs. There is a little room Left at the top but I do not believe it is enough for the an extra 5 lbs or more. The smaller container fits perfectly on top of the bigger one. With a little cut out to secure the top to the bottom makes it easy to move around. The smaller container is perfect for bags of treat, toys, scoops etc. These containers worked out pefectly for us and we will probably buy another one or bigger one, if they have one, when we get another dog. I definitely recommend keeping the pet food, whatever size you get, in the bag while in the container because it makes it easy for clean up and ensuring that all the dog food is used.