Kaizen Boxes are a flexible system that allow you to store and organize efficiently. Featuring Lean cardboard construction, they are easy to modify and tailor specifically to your needs. Available in short and long sizes with included dividers. Kaizen Box Long: 9 dividers included. Kaizen Box Short: 3 dividers included. Kaizen Boxes ship unassembled with instructions. Go to our Erasable Kaizen Labels.